Temperature control system

Abstract

Temperature control system (1), comprising: an air conditioning circuit (10) for circulating an air conditioning heating medium and for adjusting the temperature of a vehicle interior by heat exchange between the air conditioning heating medium and the air in the interior; a battery temperature control circuit (20) for circulating a battery heating medium and for adjusting the temperature of a battery (24) by heat exchange between the battery heating medium and the battery (24); a heat exchanger (30) for exchanging heat between the air conditioning heating medium and the battery heating medium; a thermometer (32) for measuring the temperature of the battery (24); and a control unit (40) for controlling the air conditioning circuit (10) and the battery temperature control circuit (20), wherein the air conditioning circuit (10) a heater (14) for heating the air conditioning heating medium, a heating core (16) for the exchange of heat between the air conditioning heating medium and the air in the interior, and a first water pump (12) for adjusting a flow rate of the air conditioning heating medium and discharging a first flow rate of the air conditioning heating medium and a second flow rate of the air conditioning heating medium, wherein the second flow rate of the air conditioning heating medium is greater than the first flow rate of the air conditioning heating medium, wherein the battery temperature control circuit (20) comprises a second water pump (22) for adjusting a flow rate of the battery heating medium and outputting a first flow rate of the battery heating medium and a second flow rate of the battery heating medium, wherein the second flow rate of the battery heating medium is greater than the first flow rate of the battery heating medium, and wherein the control unit (40) is designed, to control a flow rate of the air conditioning heating medium and the battery heating medium variably depending on a requirement to increase the temperature of the battery (24), a requirement to heat the vehicle interior and the temperature of the battery (24), in response to the detection that a charging request has been made, to the subsequent receipt of the request to increase the temperature of the battery (24), to the subsequent receipt of the request to heat the vehicle interior, to the subsequent receipt of the request to maximize the heating power, and to the subsequent receipt of the detection that the temperature of the battery (24) is lower than a setpoint temperature, to adjust the first water pump (12) so that it outputs the second flow rate of the air conditioning heating medium, to adjust the second water pump (22) so that it delivers the second flow rate of the battery heating medium, and to activate a bypass path on which the air conditioning heating medium flows from the heater (14) to the heat exchanger (30) bypassing the heating core (16), so that the flow rate of the air conditioning heating medium to the heating core (16) is reduced.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] This application claims priority over the Japanese patent application JP 2022-21580, filed on February 15, 2022. TECHNICAL AREA

[0002] The present invention relates to a temperature control system for heating a battery and for heating the interior of a vehicle. BACKGROUND

[0003] JP 2020-55342A discloses a thermal management system for a vehicle, comprising a refrigerant circuit for circulating a refrigerant to regulate the temperature in the vehicle interior, a heating circuit for circulating a fluid for heat exchange with the refrigerant to regulate the temperature of the vehicle interior, and a battery temperature control circuit for introducing the fluid for heat exchange with the refrigerant into a high-voltage battery to regulate the temperature of the high-voltage battery. The heating circuit includes a high-voltage heater for heating the circulating fluid.

[0004] In this way, this thermal management system can use the high-voltage heater to heat the vehicle interior and increase the temperature of the high-voltage battery.

[0005] A temperature control system comprising an air conditioning circuit for circulating an air conditioning heating medium and for adjusting the temperature of a vehicle interior by heat exchange between the air conditioning heating medium and the interior air, a battery temperature control circuit for circulating a battery heating medium and for adjusting the battery temperature by heat exchange between the battery heating medium and the battery, a heat exchanger for exchanging heat between the air conditioning heating medium and the battery heating medium, and a control unit for controlling the air conditioning circuit and the battery temperature control circuit is known from CN 1 13 352 839 A. Furthermore, DE 10 2013 206 651 A1 discloses a system for heating a battery in a hybrid vehicle using exhaust gas. SUMMARY

[0006] JP 2020-55 342 A discloses that the vehicle interior is heated using the fluid heated by the high-voltage heater, and that the fluid is introduced into the battery temperature control circuit to increase the temperature of the high-voltage battery. To utilize the heat from the high-voltage heater for both increasing the battery temperature and heating the vehicle interior, the heat must be divided between heating the battery and heating the interior, depending on the situation. However, this division is not addressed in JP 2020-55 342 A.

[0007] According to one aspect of the present invention, a temperature control system is provided comprising an air conditioning circuit for circulating an air conditioning heating medium and for adjusting the temperature of a vehicle interior by heat exchange between the air conditioning heating medium and the air in the interior; a battery temperature control circuit for circulating a battery heating medium and for adjusting the temperature of a battery by heat exchange between the battery heating medium and the battery; a heat exchanger for exchanging heat between the air conditioning heating medium and the battery heating medium; a thermometer for measuring the temperature of the battery; and a control unit for controlling the air conditioning circuit and the battery temperature control circuit.The air conditioning circuit comprises a heater for heating the air conditioning heating medium, a heating core for heat exchange between the air conditioning heating medium and the interior air, and a first water pump for adjusting the flow rate of the air conditioning heating medium and delivering a first flow rate and a second flow rate of the air conditioning heating medium, the second flow rate being greater than the first. The battery temperature control circuit comprises a second water pump for adjusting the flow rate of the battery heating medium and delivering a first flow rate and a second flow rate of the battery heating medium, the second flow rate being greater than the first. The control unit is configured as follows: to control the flow rate of at least one of the air conditioning heating medium and the battery heating medium variably depending on a requirement to increase the temperature of the battery, a requirement to heat the vehicle interior and the temperature of the battery, In response to the detection of a charging request, the subsequent receipt of a request to increase the battery temperature, the subsequent receipt of a request to heat the vehicle interior, the subsequent receipt of a request to maximize heating power, and the subsequent receipt of a detection that the battery temperature is lower than a setpoint temperature, adjust the first water pump to deliver the second flow rate of the air conditioning heating medium, adjust the second water pump to deliver the second flow rate of the battery heating medium, and activate a bypass path through which the air conditioning heating medium flows from the heater to the heat exchanger, bypassing the heating core, thus reducing the flow rate of the air conditioning heating medium to the heating core.

[0008] In one embodiment, the control unit can be designed to, in response to the detection that a charging request has been made, the subsequent reception of the request to increase the battery temperature, the subsequent reception of the request to heat the vehicle interior, the subsequent reception of the request to maximize the heating power, and the subsequent reception of the detection that the battery temperature is not lower than the setpoint temperature, adjust the first water pump to deliver the first flow rate of the air conditioning heating medium, adjust the second water pump to deliver the first flow rate of the battery heating medium, and shut off the bypass path so that the entire flow rate of the air conditioning heating medium flows to the heating core.

[0009] In one embodiment, the requirement to increase the battery temperature can be a requirement made for fast charging of the battery.

[0010] According to the present invention, it is possible to appropriately allocate the heat to be used between increasing the temperature of a battery and heating the vehicle interior by variably controlling the flow rate of a heating medium for a battery based on a requirement to increase the temperature of the battery, a requirement to heat the vehicle interior and the temperature of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The embodiment(s) of the present invention is / are described with reference to the following figures, showing: Fig. 1 a block diagram representing the system structure of a temperature control system according to one embodiment; Fig. 2 a flowchart of a process for controlling an air conditioning circuit 10 and a battery temperature control circuit 20; and Fig. 3 a graph showing the change in the duty cycle over time in the respective cases where a water pump 22 outputs a high flow rate and a normal flow rate. DESCRIPTION OF EXECUTION FORMS

[0012] One embodiment of the present invention will now be described with reference to the accompanying drawings. It should be noted that the present invention is not limited to the embodiment described here. System structure

[0013] Fig. Figure 1 is a block diagram showing the system structure of a temperature control system according to one embodiment. It is assumed that this system is installed in a vehicle.

[0014] The temperature control system 1 comprises an air conditioning circuit 10, a battery temperature control circuit 20, and a heat exchanger 30. The heat exchanger 30 serves for heat exchange between the air conditioning circuit 10 and the battery temperature control circuit 20.

[0015] The air conditioning circuit 10 is a circuit for circulating an air conditioning heating medium and comprises a water pump (HP) 12, a heater 14, and a heating core 16. The water pump 12 circulates the air conditioning heating medium, which is then heated by the heater 14, thus increasing the temperature of the air conditioning heating medium. The heated air conditioning heating medium then passes through the heating core 16, where it undergoes heat exchange with the air in the vehicle interior (hereinafter referred to as the interior or passenger compartment), thus increasing the temperature of the air in the interior. The heater 14 is hereinafter referred to as the heating unit.

[0016] The heating medium for the air conditioning system is a liquid such as water with a rust inhibitor (water containing rust-inhibiting material). A variety of liquid pumps can be used as the water pump 12. The heater 14 is an electric heater powered by a battery installed in the vehicle, which generates heat. The heater 14 warms the air conditioning heating medium flowing in a path by heat transfer. The heating core 16 is a heat exchanger in which the air in the interior, outside the path through which the air conditioning heating medium flows, is heated by heat exchange, thus increasing its temperature. A blower 18 is provided to draw air from the interior or passenger compartment into the heating core 16. It should be noted that the water pump 12 is referred to below as the air conditioning flow rate control unit.

[0017] A branch valve 44 is located in a channel extending from the heater 14 to the heating core 16. The branch valve 44 allows part or all of the air conditioning heating medium flowing from the heater 14 to flow to the heat exchanger 30, bypassing the heating core 16.

[0018] The battery temperature control circuit 20 is a circuit for circulating a battery heating medium. Specifically, the water pump (WP) 22 circulates the battery heating medium, which then flows through a battery 24, thus heating the battery 24 through heat exchange and increasing its temperature. It should be noted that the water pump 22 is referred to below as the battery flow rate control unit.

[0019] A liquid, such as water, similar to the heating medium used in air conditioning systems, can be used as the heating medium for the battery or battery heating medium. A pump similar to water pump 12 can be used for water pump 22.

[0020] For example, a lithium-ion battery is used as battery 24. Specifically, a predetermined voltage is ensured by a fixed number of battery cells connected in series, and a predetermined battery capacity is ensured by battery cells connected in parallel. The output voltage of battery 24 is typically 100 V or higher and is used to power a vehicle's drive motor. Furthermore, the output voltage of battery 24 is reduced by a DC-DC converter before it is used to charge an auxiliary battery. The heater 14 can be powered by the auxiliary battery or directly by battery 24. A channel for the battery heating medium is formed within a housing containing battery 24. Battery 24 is heated by heat exchange within the channel, thus increasing its temperature.

[0021] The heat exchanger 30 includes a channel for the air conditioning heating medium and a channel for the battery heating medium, which are arranged next to each other so that heat is exchanged between these channels.

[0022] The battery 24 has a thermometer 32 for measuring the battery temperature (the temperature of the battery cells). The battery temperature measured by the thermometer 32 is transmitted to a controller or control unit 40.

[0023] The control unit 40 receives various pieces of information, such as the interior temperature, the state of a heater switch (a heating request), and a charging request to charge battery 24, and controls, for example, the operation of water pumps 12, 22, or the like. Upon receiving a charging request to charge battery 24, if battery 24 is at a low temperature, the control unit 40 activates the battery temperature control circuit 20 to heat the battery 24 and thus increase its temperature. Upon receiving a heating request, the control unit 40 activates the climate control circuit 10 to heat the interior. It should be noted that the battery temperature control circuit 20 increases the temperature of battery 24 by utilizing the heat from the heat exchanger 30, i.e., the heater 14.Therefore, if the battery temperature needs to be increased and the interior heated simultaneously, the heat from heater 14 is used in both the climate control circuit 10 and the battery temperature control circuit 20. For this purpose, the control unit 40 regulates the distribution of heat from heater 14. Control Panel

[0024] Fig. Figure 2 is a flowchart of a process for controlling the air conditioning circuit 10 and the battery temperature control circuit 20 by the control unit 40.

[0025] First, it is determined whether a charging request, in particular a fast-charging request, has been made (S11). This corresponds, for example, to the case where the battery of a parked vehicle is to be charged with electricity from an external fast charger. Fast charging can also include the case where a hybrid electric vehicle is charged with electricity generated by an internal combustion engine or with renewable electricity recovered through regenerative braking (recuperation).

[0026] If the answer to question S11 is NO, charging is unnecessary, and the current processing is terminated. If, however, the answer to question S11 is YES, it is determined whether the battery temperature is lower than a target temperature 1 (S12). It should be noted that target temperature 1 is a reference point used to determine whether an increase in battery temperature 24 is necessary and is set, for example, to approximately 5 to 10°C. If the battery temperature is not lower than target temperature 1, an increase in battery temperature is not necessary, and the current processing is terminated.

[0027] If the answer to question S12 is YES, it is determined whether a heating request has been made (S13). If the answer to question S13 is NO, no allocation is necessary, and the current processing is terminated. It should be noted that the presence of a heating request can be determined by whether a switch for heating the interior has been turned on, as described above. If, on the other hand, the answer to question S13 is YES, the output of heater 14 is maximized (S14). In particular, if both a battery temperature increase request and a heating request have been made, heater 14 is set to generate the maximum amount of heat before the heat is allocated, as a large amount of heat is required.

[0028] The system then checks whether the battery temperature is lower than a target temperature 2 (S15). The target temperature 2 is set to approximately 0°C, for example. This is because as soon as the battery temperature falls to 0°C or below, the battery's charging characteristics deteriorate significantly, necessitating an increase in the battery temperature 24.

[0029] If the answer to question S15 is YES, the water pump 12 of the air conditioning circuit 10 is set to deliver a high flow rate, and the diverter valve (a three-way valve) 44 is controlled to open the bypass, i.e., to divert the air conditioning heating medium into the bypass (S16). The amount of air conditioning heating medium to be diverted into the bypass can be predetermined. For example, approximately 50% of the total amount of air conditioning heating medium can be diverted into the bypass. Alternatively, the amount to be diverted can be adjusted so that a larger amount is diverted when the battery temperature is lower.

[0030] In addition, the water pump 22 of the battery temperature control circuit 20 is set to output a high flow rate (S17).

[0031] As described above, if the answer to question S15 is YES, the power of heater 14 is maximized to maximize heating output. Then, the amount of air conditioning heating medium flowing through heat exchanger 30 of air conditioning circuit 10 is increased, as is the amount of battery heating medium flowing through heat exchanger 30 of battery temperature control circuit 20. This increases the amount of battery heating medium flowing through battery 24, thus raising its temperature. This results in a greater heating of battery 24, which can accelerate the temperature increase within battery 24. Simultaneously, a smaller amount of air conditioning heating medium flows through heating core 16, leading to insufficient heating of the interior. In other words, processing is prioritized to increase the battery temperature.

[0032] If, on the other hand, the answer to question S15 is NO, the water pump 12 of the air conditioning circuit 10 is set to deliver a normal flow rate, and the diverter valve 44 is set to shut off the bypass, i.e., no air conditioning heating medium flows into the bypass (S18). The water pump 22 of the battery temperature control circuit 20 is set to deliver a normal flow rate (S19).

[0033] As described above, if the answer to question S15 is NO, the output of heater 14 is maximized in a similar way to when question S15 is answered YES, but it is set so that a normal amount of air conditioning heating medium flows through heat exchanger 30 of air conditioning circuit 10 and the bypass of air conditioning circuit 10 is switched off, so that all of the air conditioning heating medium flows into the heating core 16. This increases the amount of air conditioning heating medium flowing through heating core 16, ensuring sufficient heating of the interior. It should be noted that the amount of air conditioning heating medium flowing through heat exchanger 30 of air conditioning circuit 10 can be increased. Additionally, it is set so that a normal amount of battery heating medium flows through heat exchanger 30 of battery temperature control circuit 20, so that a normal amount of battery heating medium flows into battery 24.Consequently, the heat exchanger 30 receives less heat than if the answer to question S15 is YES. This means that the temperature increase of battery 24 is limited to some extent.

[0034] As described above, if the determination in S15 is answered with NO, the processing for heating the interior will be carried out with priority over increasing the temperature of battery 24.

[0035] Fig.Figure 3 illustrates the change in the duty cycle or duty ratio of the power supplied to water pump 22 in the respective cases where water pump 22 delivers a high flow rate and a normal flow rate. As shown, a long duty cycle is set for a high flow rate. In this case, the flow rate increases rapidly until the set duty cycle is reached. For a normal flow rate, on the other hand, a relatively short duty cycle is set. The duty cycle setting described above allows the flow rate delivered by water pump 22 to be adjusted. It should be noted that the flow rate delivered by water pump 12 can be controlled by a duty cycle in a similar way to the one described above.

[0036] The embodiment described above is related to an increase in the temperature of battery 24 during fast charging. The performance of the battery cell decreases when the battery is at a low temperature and is also being charged. To counteract this, the processing described above can be applied when there is a requirement to increase the temperature of battery 24 while it is at a low temperature, and simultaneously when heating is required.

[0037] In the case of YES in S15, i.e., in the case where increasing the temperature of battery 24 is performed with priority, the blower 18 can be set to blow a smaller amount of air, so that the heating core 16 emits a smaller amount of heat and a larger amount of heat can be used to increase the temperature of battery 24.

[0038] If S15 is set to NO, meaning that the interior is being heated as a priority, the interior temperature can be measured so that the amount of air blown by the blower 18 is automatically adjusted depending on the difference between the measured temperature and a target temperature. That is, the blower 18 can blow out a larger volume of air when the difference between the measured temperature and a target temperature is large, allowing the interior temperature to approach the target temperature. Conversely, if the difference to the target temperature is small, the flow rate delivered by the water pump 12 can be automatically adjusted depending on the difference to the target temperature. That is, the water pump 12 can be set to deliver a higher flow rate when the difference to the target temperature is large. REFERENCE MARK LIST 1 Temperature control system 10 Air conditioning circuit 12 Water pump 14 Heating 16 heating cores 18 blowers 20 Battery temperature control circuit 22 Water pump 24 battery 30 heat exchangers 32 Thermometer 40 Control unit 44 Branch valve

Claims

[1] Temperature control system (1) comprising: an air conditioning circuit (10) for circulating an air conditioning heating medium and for adjusting the temperature of a vehicle interior by heat exchange between the air conditioning heating medium and the air in the interior; a battery temperature control circuit (20) for circulating a battery heating medium and for adjusting the temperature of a battery (24) by heat exchange between the battery heating medium and the battery (24); a heat exchanger (30) for exchanging heat between the air conditioning heating medium and the battery heating medium; a thermometer (32) for measuring the temperature of the battery (24); and a control unit (40) for controlling the air conditioning circuit (10) and the battery temperature control circuit (20), wherein the air conditioning circuit (10) a heater (14) for heating the air conditioning heating medium, a heating core (16) for the exchange of heat between the air conditioning heating medium and the air in the interior, and a first water pump (12) for adjusting a flow rate of the air conditioning heating medium and discharging a first flow rate of the air conditioning heating medium and a second flow rate of the air conditioning heating medium, wherein the second flow rate of the air conditioning heating medium is greater than the first flow rate of the air conditioning heating medium, wherein the battery temperature control circuit (20) comprises a second water pump (22) for adjusting a flow rate of the battery heating medium and outputting a first flow rate of the battery heating medium and a second flow rate of the battery heating medium, wherein the second flow rate of the battery heating medium is greater than the first flow rate of the battery heating medium, and wherein the control unit (40) is designed, to control a flow rate of the air conditioning heating medium and the battery heating medium variably depending on a requirement to increase the temperature of the battery (24), a requirement to heat the vehicle interior and the temperature of the battery (24), in response to the detection that a charging request has been made, to the subsequent receipt of the request to increase the temperature of the battery (24), to the subsequent receipt of the request to heat the vehicle interior, to the subsequent receipt of the request to maximize the heating power, and to the subsequent receipt of the detection that the temperature of the battery (24) is lower than a setpoint temperature, to adjust the first water pump (12) so that it outputs the second flow rate of the air conditioning heating medium, to adjust the second water pump (22) so that it delivers the second flow rate of the battery heating medium, and to activate a bypass path on which the air conditioning heating medium flows from the heater (14) to the heat exchanger (30) bypassing the heating core (16), so that the flow rate of the air conditioning heating medium to the heating core (16) is reduced. [2] Temperature control system (1) according to claim 1, wherein the control unit (40) is designed to respond, in response to the detection that a charging request has been made, to the subsequent reception of the request to increase the temperature of the battery (24), to the subsequent reception of the request to heat the vehicle interior, to the subsequent reception of the request to maximize the heating power, and to the subsequent reception of the detection that the temperature of the battery (24) is not lower than the setpoint temperature, to adjust the first water pump (12) so that it delivers the first flow rate of the air conditioning heating medium, to adjust the second water pump (22) so that it delivers the first flow rate of the battery heating medium, and to shut off the bypass path so that the entire flow rate of the air conditioning heating medium flows to the heating core (16). [3] Temperature control system (1) according to claim 1 or 2, wherein the requirement to increase the temperature of the battery (24) is a requirement made for fast charging of the battery (24).

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