Vehicle air conditioning system

Abstract

To provide a vehicle air conditioning system that can reduce losses when utilizing regenerative power. [Solution] When regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22. If the regenerative power supplied to the heat transfer medium heating device 22 exceeds the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium, the amount of heat dissipated from the heat transfer medium by the heater core 21 is increased by lowering the temperature of the air flowing into the heater core 21.

Description

Technical Field

[0001] The present invention relates to a vehicle air conditioner.

Background Art

[0002] Conventionally, a vehicle air conditioner that utilizes regenerative power has been known (for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a vehicle air conditioner capable of suppressing losses when utilizing regenerative power.

Means for Solving the Problems

[0005] According to one aspect of the present invention, a vehicle air conditioner includes a battery, a power generation device capable of generating regenerative power, a heat medium circuit in which a heat medium that adjusts the temperature of the air supplied into the vehicle interior circulates by a heater core, and a heat medium heating device that heats the heat medium. When regenerative power is generated during heating operation, the regenerative power is supplied to the heat medium heating device. When the regenerative power supplied to the heat medium heating device exceeds the target power of the heat medium heating device based on the target temperature of the heat medium, the temperature of the air flowing into the heater core is lowered to increase the heat dissipation amount of the heat medium in the heater core.

Effects of the Invention

[0006] According to the present invention, it is possible to provide a vehicle air conditioning system that can suppress losses when utilizing regenerative power. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a circuit diagram showing an example of the configuration of a vehicle air conditioning system. [Figure 2] Figure 2 is a flowchart showing an example of regenerative power utilization processing. [Figure 3] Figure 3 is a flowchart showing an example of the heat storage priority mode execution process. [Figure 4] Figure 4 is a flowchart showing an example of the comfort-prioritized mode execution process. [Figure 5] Figure 5 is an explanatory diagram illustrating an example of the relationship between the temperature of the heat transfer medium, the battery power, and the regenerative power when the heat storage priority mode is executed. [Figure 6] Figure 6 is an explanatory diagram illustrating an example of the relationship between the temperature of the heat transfer medium, the battery power, and the regenerative power when the heat storage priority mode is executed. [Figure 7] Figure 7 is an explanatory diagram illustrating an example of the relationship between the temperature of the heat transfer medium, the battery power, and the regenerative power when comfort-priority mode is activated. [Figure 8] Figure 8 is an explanatory diagram illustrating an example of the relationship between the temperature of the heat transfer medium, the battery power, and the regenerative power when comfort-priority mode is activated. [Figure 9] Figure 9 is an explanatory diagram illustrating an example of the relationship between the temperature of the heat transfer medium, the battery power, and the regenerative power when comfort-priority mode is activated. [Modes for carrying out the invention]

[0008] [Configuration of a vehicle air conditioning system] <Overview of Vehicle Air Conditioning Systems> Figure 1 is an explanatory diagram illustrating the schematic of a vehicle air conditioning system 1. The vehicle air conditioning system 1 is mounted on a vehicle. The vehicle is preferably a vehicle equipped with a battery for driving. The vehicle may be, for example, an electric vehicle (BEV: Battery Electric Vehicle), a hybrid vehicle (HEV: Hybrid Electric Vehicle), a plug-in hybrid vehicle (PHEV: Plug-in Hybrid Electric Vehicle), or a fuel cell vehicle (FCEV: Fuel Cell Electric Vehicle).

[0009] The vehicle air conditioning system 1 comprises a heat transfer medium circuit 20, a refrigerant circuit 30, an HVAC unit 100, and a control device 200.

[0010] <Heating medium circuit> In the heat transfer circuit 20, a fluid heat transfer medium, such as coolant, circulates. The heat transfer circuit 20 comprises a heater core 21, a circulation pump P20, a heat transfer medium heating device 22, a battery 23, a power generator 24, and a circuit switching device 25. The heater core 21 heats the air supplied to the vehicle interior. The heater core 21 functions by the heat transfer medium radiating heat from the heater core 21. The heat transfer circuit 20 can be used to heat the vehicle interior by making the heater core 21 function. The circulation pump P20 pushes the heat transfer medium and circulates it in the heat transfer circuit 20. The heat transfer medium heating device 22 heats the heat transfer medium circulating in the heat transfer circuit 20.

[0011] The battery 23 can be charged with power received from the vehicle or from an external source. The generator 24 can generate regenerative power generated by the vehicle's operation. The circuit switching device 25 can switch the connection or disconnection between the heat transfer medium heating device 22, the battery 23, and the generator 24.

[0012] The circuit switching device 25 includes a switch 25a, a switch 25b, and a switch 25c. The switch 25a switches between connecting and disconnecting the power generation device 24 and the heat medium heating device 22. The switch 25b switches between connecting and disconnecting the battery 23 and the heat medium heating device 22. The switch 25c switches between connecting and disconnecting the battery 23 and the power generation device 24.

[0013] When the switch 25a is connected, the power generated by the power generation device 24 can be supplied to the heat medium heating device 22. When the switch 25b is connected, the power charged in the battery 23 can be supplied to the heat medium heating device 22. When the switch 25c is connected, the power generated by the power generation device 24 can be supplied to the battery 23.

[0014] 〈Refrigerant Circuit〉 In the refrigerant circuit 30, for example, a refrigerant such as hydrofluoroolefin circulates. The refrigerant circuit 30 functions as a heat pump that circulates the refrigerant and repeats compression, condensation, expansion, and evaporation. The refrigerant circuit 30 includes a cooler core 31, an outdoor heat exchanger 32, a compressor 33, and a decompression device 34. The compressor 33 compresses the gaseous refrigerant to a high temperature and high pressure and then discharges it. The outdoor heat exchanger 32 condenses the compressed gaseous refrigerant and releases heat. The decompression device 34 expands the liquid refrigerant to a low pressure. The cooler core 31 evaporates the liquid refrigerant that has been reduced to a low temperature and low pressure and absorbs heat. The refrigerant circuit 30 can be used to cool or dehumidify the vehicle interior by functioning the cooler core 31.

[0015] 〈HVAC Unit〉 The heater core 21 of the heat medium circuit 20 and the cooler core 31 of the refrigerant circuit 30 are housed in the case 110 of the HVAC unit 100. The case 110 forms the outer shell of the HVAC unit 100 and forms an air flow path 120 inside.

[0016] The HVAC unit 100 includes an intake unit 130. The intake unit 130 closes either the outside air inlet for introducing outside air of the vehicle compartment or the inside air inlet for introducing inside air of the vehicle compartment, and switches the air introduced into the case 110 to either outside air of the vehicle compartment (outside air introduction) or inside air of the vehicle compartment (inside air circulation). Further, the HVAC unit 100 includes a blower 140 installed adjacent to the intake unit 130 so that the air introduced into the case 110 is introduced into the air flow passage 120.

[0017] A cooler core 31 is arranged upstream of the air flow passage 120, and a heater core 21 is arranged downstream of the cooler core 31 in the air flow passage 120. Further, a heater core passage 121 and a bypass passage 122 are formed in parallel downstream of the air flow passage 120. The heater core passage 121 is provided downstream of the heater core 21. Therefore, when the air introduced into the case 110 is induced into the heater core passage 121, the air is ventilated through the cooler core 31 and then through the heater core 21. On the other hand, when the air introduced into the case 110 is induced into the bypass passage 122, the air bypasses without passing through the heater core 21 after being ventilated through the cooler core 31. And the ratio of the air passing through the heater core passage 121 and the air passing through the bypass passage 122 is adjusted by the air mix damper 150.

[0018] <Control device> The control device 200 includes a processor, memory, storage, and an interface. The processor is, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). The memory is, for example, RAM (Random Access Memory). The storage is rewritable non-volatile memory such as an HDD (Hard Disk Drive), SSD (Solid State Drive), or flash memory. The storage stores a system program including an OS (Operating System) and a control program including computer-readable code necessary for control calculations. The processor performs various processes by reading the system program and the control program, loading them into memory, and executing them. The interface controls communication between the control device 200 and the components of the vehicle air conditioning system 1.

[0019] The control device 200 controls the operation of the vehicle air conditioning system 1 according to the operations required of the vehicle (e.g., air conditioning inside the vehicle). The control device 200 receives detection information from various sensors provided by the vehicle air conditioning system 1. For example, it includes a heat transfer medium temperature sensor 210 that detects the temperature of the heat transfer medium circulating in the heat transfer medium circuit 20.

[0020] The control device 200 controls the operation of the power generator 24, the charging or discharging of the battery 23, the operation of the circulation pump P20, the operation of the compressor 33, the operation of the pressure reducing device 34, the operation of the blower 140, etc., based on detection information from various sensors.

[0021] [Operation of the vehicle's air conditioning system 1] The specific operation of the vehicle air conditioning system 1 will be explained below. <Heater operation> Figure 1 shows the state of the vehicle air conditioning system 1 when the air conditioning mode is set to heating mode and heating operation is performed when the outside temperature is low.

[0022] In other words, in the heat transfer medium circuit 20, the heat transfer medium is circulated by being pushed out by the circulation pump P20. At this time, the heat transfer medium heated by the heat transfer medium heating device 22 flows to the heater core 21, and the heat transfer medium flowing through the heater core 21 dissipates heat. In addition, the air mix damper 150 opens the heater core passage 121. As a result, the interior of the vehicle is heated by the air that has passed through the heater core 21 due to the air blown by the blower 140.

[0023] Furthermore, during heating operation, the compressor 33 in the refrigerant circuit 30 is stopped. Therefore, the refrigerant circuit 30 does not function during heating operation. Consequently, the cooler core 31 also does not function.

[0024] <Regenerative power utilization processing> Next, the regenerative power utilization process performed by the control device 200 when the power generation device 24 generates regenerative power will be explained using Figure 2.

[0025] Traditionally, when regenerative power was generated, it was used to charge the battery. However, when regenerative power is used to charge the battery, power loss occurs during the charging / discharging process and the electrical conversion process due to factors such as the battery's internal resistance and temperature rise.

[0026] Therefore, in this embodiment, by executing the regenerative power utilization process shown in Figure 2, it is possible to switch to a regenerative power utilization mode that utilizes regenerative power without loss. As a result, in this embodiment, regenerative power can be consumed by the heat transfer medium heating device 22, which has high conversion efficiency, without charging the battery 23. Thus, regenerative power can be utilized more efficiently than when charging the battery 23.

[0027] As shown in Figure 2, in the regenerative power utilization process, the control device 200 first determines whether or not heating operation is in progress (S1).

[0028] If the control device 200 determines that heating operation is not in progress (S1: NO), it terminates the process.

[0029] If the control device 200 determines that heating operation is in progress (S1: YES), it determines whether or not regenerative power has been generated (S2).

[0030] If the control device 200 determines that no regenerative power is being generated (S2:NO), it terminates the process. If no regenerative power is being generated, the control device 200 connects only switch 25b and not switch 25a, thereby supplying only battery power, which is the power from the battery 23, to the heat transfer medium heating device 22. As a result, the heat transfer medium heating device 22 operates using only battery power.

[0031] If the control device 200 determines that regenerative power has been generated (S2: YES), it supplies the regenerative power to the heat transfer medium heating device 22 by connecting the heat transfer medium heating device 22 and the power generation device 24 using the switch 25a (S3).

[0032] The control device 200 determines whether the regenerative power supplied to the heat transfer medium heating device 22 exceeds the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium (S4). The target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium is the power required to heat the heat transfer medium so that its temperature reaches the target temperature. Therefore, it can be said that step S4 determines whether the temperature of the heat transfer medium exceeds the target temperature.

[0033] The control device 200 terminates the process if it determines that the regenerative power supplied to the heat transfer medium heating device 22 does not exceed the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium (S4:NO). At this time, the control device 200 supplies regenerative power and battery power to the heat transfer medium heating device 22 by connecting both switch 25a and switch 25b. As a result, the heat transfer medium heating device 22 operates using the regenerative power and battery power.

[0034] If the control device 200 determines that the regenerative power supplied to the heat transfer medium heating device 22 exceeds the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium (S4: YES), it selects either the heat storage priority mode or the comfort priority mode (S5). If the regenerative power supplied to the heat transfer medium heating device 22 exceeds the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium, the control device 200 supplies only the regenerative power to the heat transfer medium heating device 22 by connecting only switch 25a and not switch 25b. As a result, the heat transfer medium heating device 22 operates using only the regenerative power.

[0035] The heat storage priority mode allows the heat transfer medium to exceed the target temperature, thereby storing heat in the medium and eliminating power consumption during the period when the heat transfer medium temperature drops back down to the target temperature, thus reducing battery power consumption. Therefore, the heat storage priority mode is advantageous for extending the driving range.

[0036] The comfort-priority mode is a mode that improves comfort inside the vehicle by increasing the amount of outside air introduced or switching to dehumidification mode to increase the amount of heat released from the heat transfer medium, thereby maintaining the temperature of the heat transfer medium at the target temperature. Therefore, the comfort-priority mode is advantageous in improving the mood of the occupants.

[0037] Furthermore, in this embodiment, by selectively executing the comfort priority mode and the heat storage priority mode in step S5, it is possible to switch between the comfort priority mode and the heat storage priority mode, thereby enabling efficient use of surplus regenerative power exceeding the target power.

[0038] Furthermore, the selection of either comfort-priority mode or heat storage-priority mode in step S5 can be made in various ways or based on various conditions.

[0039] As an example of a selection method in step S5, one can cite an example where either a heat storage priority mode or a comfort priority mode is selected based on the occupant's selection operation. In this case, it is preferable to recommend one of the modes when the occupant makes their selection operation.

[0040] In other words, it is preferable that the control device 200 stores information indicating the selection history of comfort-priority mode and heat storage-priority mode, and information indicating the environment when either comfort-priority mode or heat storage-priority mode is selected, and selects which of the two modes, comfort-priority mode or heat storage-priority mode, to recommend based on the information stored by the control device 200. This prevents occupants from feeling inconvenienced when choosing between comfort-priority mode and heat storage-priority mode, as they only need to select the recommended mode.

[0041] As a concrete example, one method involves storing information indicating the selection history until regenerative power is generated a certain number of times, as well as information indicating the environment inside the vehicle, such as temperature, humidity, time of day, location, and amount of sunlight, when comfort-priority mode or heat storage-priority mode is selected. This allows for the identification of the occupant's preferences, and then recommending either comfort-priority mode or heat storage-priority mode based on the identified preferences. In this case, allowing AI to learn would enable more accurate identification of the occupant's preferences.

[0042] Furthermore, when identifying occupant preferences, if the system also stores information such as the occupant's driving style (accelerator use, braking frequency, etc.) or the air conditioning settings history, it can more accurately identify the occupant's preferences. In this case, if the occupant tends to drive in a way that prioritizes fuel efficiency, the system can determine that the heat storage priority mode is the occupant's preference and select that mode. Also, if the air conditioning settings are frequently adjusted, the system can determine that the comfort priority mode is the occupant's preference and select that mode. When using the air conditioning settings history, combining conditions such as cabin temperature, humidity, time of day, location, and sunlight level through AI learning can lead to more accurate determinations.

[0043] Alternatively, the system may automatically select either comfort-priority mode or heat storage-priority mode based on information showing the selection history of comfort-priority mode or heat storage-priority mode, and information showing the environment when comfort-priority mode or heat storage-priority mode was selected. In this case, the occupants are saved the trouble of selecting a mode, thus preventing them from feeling inconvenienced by the choice between comfort-priority mode and heat storage-priority mode.

[0044] Furthermore, as an example of a selection method in step S5, one can cite the example of selecting either a heat storage priority mode or a comfort priority mode based on the air quality inside and outside the vehicle.

[0045] In this case, the control device 200 acquires information indicating the air quality inside and outside the vehicle, and it is preferable to prioritize the heat storage priority mode if the air quality outside the vehicle is better than the air quality inside the vehicle. This makes it possible to actively take in outside air when the outside air quality is good and not take in outside air when the outside air quality is poor, thereby improving comfort.

[0046] As a specific example, one method is to select comfort-priority mode when the air quality outside the vehicle deteriorates beyond a certain value based on information obtained via the internet or directly measured, and to select heat storage-priority mode until the air quality outside the vehicle exceeds a certain value. Another example is to select comfort-priority mode when the CO2 concentration inside the vehicle is above a certain level (i.e., above a threshold), and to select heat storage-priority mode until the CO2 concentration inside the vehicle reaches a certain level. It is preferable to determine air quality by combining multiple criteria, such as humidity, CO2 concentration, dust concentration, and odor concentration.

[0047] Furthermore, as an example of a selection method in step S5, one can cite an example of selecting either a heat storage priority mode or a comfort priority mode based on the difference between the temperature of the heat transfer medium and a predetermined allowable upper temperature limit of the heat transfer medium. The predetermined allowable upper temperature limit is, for example, a temperature at which a malfunction may occur in the heat transfer medium circuit 20.

[0048] In this case, if the difference between the temperature of the heat transfer medium and a predetermined allowable upper temperature limit falls below a predetermined level while the heat storage priority mode is running, it is preferable to prioritize the comfort priority mode. This prevents malfunctions from occurring in the heat transfer medium circuit 20 due to excessive heat storage.

[0049] As a concrete example, one can cite an example where the comfort-priority mode is selected when the difference between the temperature of the heat transfer medium and a predetermined allowable upper temperature is below a certain temperature, and the heat storage-priority mode is selected when the difference between the temperature of the heat transfer medium and a predetermined allowable upper temperature exceeds a certain temperature. In other words, this prevents the heat transfer medium from storing heat by selecting the heat storage-priority mode even though the temperature of the heat transfer medium is approaching the predetermined allowable upper temperature. Another example is where the comfort-priority mode is selected when the temperature of the heat transfer medium is higher than the target temperature, and the heat storage-priority mode is selected when the temperature of the heat transfer medium is lower than the target temperature.

[0050] If the control device 200 selects the heat storage priority mode (S6:YES), it will execute the heat storage priority mode (S7). If the control device 200 selects the comfort priority mode (S6:NO), it will execute the comfort priority mode (S8).

[0051] <Heat storage priority mode execution process> Next, the heat storage priority mode execution process performed by the control device 200 in step S7 of Figure 2 will be explained using Figure 3.

[0052] As shown in Figure 3, in the heat storage priority mode, the control device 200 first allows the temperature of the heat transfer medium to exceed the target temperature within a range that is below a predetermined allowable temperature (S10). The predetermined allowable temperature is a temperature at which the occupants do not feel any change in the temperature of the air blown into the passenger compartment via the heater core 21, even if the temperature of the heat transfer medium exceeds the target temperature. In other words, the allowable temperature is a temperature range that does not impair comfort.

[0053] Then, through the process in step S10, if the temperature of the heat medium exceeds the target temperature, the heat exceeding the target temperature can be stored in the heat medium. In this way, by allowing the temperature of the heat medium to exceed the target temperature within a range that does not impair comfort, the consumption of regenerative power in the heat medium heating device 22 increases, so that the regenerative power can be preferentially used in the heat medium heating device 22. This reduces the loss when using regenerative power compared to charging the battery 23 with the regenerative power first.

[0054] At this time, it is possible to lower the temperature of the air flowing to the heater core 21 by increasing the amount of outside air introduced or switching to dehumidification mode, or to increase the amount of airflow in the bypass passage 122 by driving the air mix damper 150. In this case, it is possible to increase the allowable temperature while preventing a deterioration in comfort, and thus increase the amount of heat that can be stored.

[0055] The control device 200 determines whether the regenerative power supplied to the heat transfer medium heating device 22 exceeds the allowable power of the heat transfer medium heating device 22 based on the allowable temperature (S11). The allowable power of the heat transfer medium heating device 22 based on the allowable temperature is the power required to heat the heat transfer medium so that its temperature reaches a predetermined allowable temperature.

[0056] If the control device 200 determines that the regenerative power supplied to the heat transfer medium heating device 22 does not exceed the allowable power of the heat transfer medium heating device 22 based on the allowable temperature (S11: NO), it executes the process in step S13.

[0057] If the control device 200 determines that the regenerative power supplied to the heat transfer medium heating device 22 exceeds the allowable power of the heat transfer medium heating device 22 based on the allowable temperature (S11: YES), it switches to the comfort maintenance mode (S12).

[0058] In comfort maintenance mode, the control device 200 increases the heat dissipation of the heater core 21 by lowering the temperature of the air flowing into the heater core 21. This allows the outlet temperature to be maintained even if the temperature of the heat transfer medium rises. Therefore, it is possible to prevent deterioration of comfort caused by allowing the temperature of the heat transfer medium to exceed the target temperature.

[0059] In other words, in comfort maintenance mode, the amount of heat dissipated by the heater core 21 is increased to lower the temperature of the heat transfer medium to below the allowable temperature, thereby increasing the regenerative power consumed by the heat transfer medium heating device 22 and maintaining the temperature of the heat transfer medium at the allowable temperature. Therefore, by switching to comfort maintenance mode, comfort can be maintained while consuming the regenerative power in the heat transfer medium heating device 22 without wasting it. This reduces the loss when using regenerative power compared to charging the battery 23 once.

[0060] In comfort maintenance mode, for example, the amount of outside air introduced is increased to lower the temperature of the air blown by the fan 140 to the heater core 21. As a result, the temperature of the air flowing into the heater core 21 decreases, so the power consumption of the heat transfer medium heating device 22 increases in order to maintain the temperature of the heat transfer medium at an acceptable temperature, and surplus power can be consumed. At this time, since the temperature of the air flowing into the heater core 21 decreases, there is a risk that the outlet temperature will decrease, so the amount of outside air introduced is adjusted to maintain the outlet temperature. Furthermore, since the vehicle interior can be ventilated by introducing outside air, the CO2 concentration inside the vehicle interior can be reduced. Therefore, it is possible to improve the air quality inside the vehicle interior and improve the comfort of the occupants.

[0061] Furthermore, for example, switching the air conditioning mode to dehumidification mode (i.e., dehumidifying heating mode) lowers the temperature of the air flowing into the heater core 21. In other words, increasing the rotational speed of the compressor 33 lowers the temperature of the refrigerant flowing through the cooler core 31. This increases the power consumption of the compressor 33, and the power consumption of the heat transfer medium heating device 22 increases in order to maintain the temperature of the heat transfer medium at an acceptable temperature, thus allowing surplus power to be consumed. The dehumidification capacity of the cooler core 31 can be improved by lowering the temperature of the refrigerant flowing through the cooler core 31. At this time, since the discharge temperature may decrease due to the decrease in the temperature of the air flowing through the heater core 21, the amount of dehumidification is adjusted so that the discharge temperature can be maintained. Thus, the comfort of the occupants can be improved, and fogging of the vehicle windows can be suppressed.

[0062] Furthermore, surplus power exceeding the allowable power may not be used to increase the heat dissipation of the heater core 21, but rather directly to improve comfort. For example, the rotation speed of the blower 140 may be increased to improve ventilation performance by increasing the amount of outside air introduced, or the rotation speed of the compressor 33 may be increased to improve dehumidification performance. Also, if surplus power is still generated even after switching to comfort maintenance mode, it is preferable to charge the battery 23 with the surplus power. In addition, the heat dissipation of the heater core 21 may be increased by increasing the amount of air blown to the heater core 21 by the blower 140 in comfort maintenance mode.

[0063] The control device 200 determines whether the regenerative power supplied to the heat transfer medium heating device 22 has fallen below the target power of the heat transfer medium heating device 22 (S13).

[0064] If the control device 200 determines that the regenerative power supplied to the heat transfer medium heating device 22 is not less than or equal to the target power of the heat transfer medium heating device 22 (S13: NO), it executes the process of step S10.

[0065] If the control device 200 determines that the regenerative power supplied to the heat transfer medium heating device 22 has fallen below the target power of the heat transfer medium heating device 22 (S13: YES), it sets the target temperature of the heat transfer medium again and terminates the process (S14).

[0066] Subsequently, the control device 200 refrains from supplying power to the heat transfer medium heating device 22 during the period when the temperature of the heat transfer medium exceeds the target temperature. Then, when the temperature of the heat transfer medium falls below the target temperature, the control device 200 supplies power from the battery 23 to the heat transfer medium heating device 22 to maintain the temperature of the heat transfer medium at the target temperature.

[0067] Thus, when the regenerative power supplied to the heat transfer medium heater 22 falls below the target power of the heat transfer medium heater 22, the control device 200 controls the temperature of the heat transfer medium so that the temperature of the heat transfer medium reaches the target temperature. As a result, heating of the heat transfer medium is not required until the temperature of the heat transfer medium reaches the target temperature due to the heat stored in the heat transfer medium, so the power consumption of the battery 23 after the generation of regenerative power is completed can be reduced. In addition, by controlling the temperature of the heat transfer medium so that the temperature of the heat transfer medium reaches the target temperature, the requirement for comfort can be met.

[0068] <Comfort-priority mode execution process> Next, the comfort-priority mode execution process performed by the control device 200 in step S8 of Figure 2 will be explained using Figure 4.

[0069] As shown in Figure 4, in comfort priority mode, the control device 200 prevents the temperature of the heat transfer medium from rising by increasing the amount of heat dissipated by the heater core 21, thereby maintaining the outlet temperature (S20).

[0070] In other words, if the heat dissipation rate of the heater core 21 is not increased, the regenerative power will exceed the target power, causing the temperature of the heat transfer medium to exceed the target temperature, and the discharge temperature to rise. Therefore, the heat dissipation rate of the heater core 21 is increased to lower the temperature of the heat transfer medium. As a result, the power of the heat transfer medium heating device 22 increases in order to maintain the temperature of the heat transfer medium at the target temperature. In other words, the power required to maintain the discharge temperature increases. Therefore, it is possible to maintain the discharge temperature while preventing the regenerative power from exceeding the target power.

[0071] Therefore, regenerative power can be consumed efficiently by the heat transfer medium heating device 22 without compromising comfort. This reduces losses when utilizing regenerative power compared to charging the battery 23 first.

[0072] In comfort-priority mode, for example, the amount of outside air introduced is increased to lower the temperature of the air blown by the fan 140 to the heater core 21. As a result, the temperature of the air flowing into the heater core 21 decreases, increasing the power consumption required to maintain the temperature of the heat transfer medium at the target temperature, thus allowing surplus power to be consumed. At this time, since the temperature of the air flowing into the heater core 21 may decrease, the amount of outside air introduced is adjusted to maintain the outlet temperature. Furthermore, since the vehicle interior can be ventilated by introducing outside air, the CO2 concentration inside the vehicle interior can be reduced. Therefore, it is possible to improve the air quality inside the vehicle interior and enhance the comfort of the occupants.

[0073] Furthermore, for example, switching the air conditioning mode to dehumidification mode (i.e., dehumidifying heating mode) lowers the temperature of the air flowing into the heater core 21. In other words, increasing the rotational speed of the compressor 33 lowers the temperature of the refrigerant flowing through the cooler core 31. This increases the power consumption of the compressor 33, and therefore increases the power consumption of the heat transfer medium heating device 22 in order to maintain the temperature of the heat transfer medium at the target temperature, thus allowing surplus power to be consumed. The dehumidification capacity of the cooler core 31 can be improved by lowering the temperature of the refrigerant flowing through the cooler core 31. At this time, since the discharge temperature may decrease due to the decrease in the temperature of the air flowing through the heater core 21, the amount of dehumidification is adjusted so that the discharge temperature can be maintained. Thus, the comfort of the occupants can be improved, and fogging of the vehicle windows can be suppressed.

[0074] Furthermore, surplus power exceeding the target power may not be used to increase the heat dissipation of the heater core 21, but rather directly to improve comfort. For example, the rotation speed of the blower 140 may be increased to improve ventilation performance by increasing the amount of outside air introduced, or the rotation speed of the compressor 33 may be increased to improve dehumidification performance. Also, if surplus power is still generated even after switching to comfort priority mode, it is preferable to charge the battery 23 with the surplus power. In addition, the heat dissipation of the heater core 21 may be increased by increasing the amount of air blown to the heater core 21 by the blower 140 in comfort priority mode.

[0075] The control device 200 determines whether the regenerative power has exceeded the surplus threshold (S21). The surplus threshold is a value used to determine whether the regenerative power generated exceeds the target power required to maintain the temperature of the heat transfer medium at the target temperature.

[0076] If the control device 200 determines that the regenerative power is not above the surplus threshold (S21: NO), it executes the process in step S23.

[0077] If the control device 200 determines that the regenerated power has exceeded a surplus threshold (S21: YES), it charges the battery 23 with the regenerated power (S22). This makes it possible to maintain the regenerated power at the target power level, thereby maintaining the temperature of the heat transfer medium at the target temperature and keeping the outlet temperature within a certain range. Furthermore, in the regenerative power utilization mode, which reduces losses when using regenerated power compared to charging the battery 23 before supplying power to the heat transfer medium heating device 22, if more regenerated power is generated than the power that can be consumed due to factors such as outside air intake or transition to dehumidification mode, the regenerated power can be effectively utilized without being wasted by supplying power to the battery 23.

[0078] In step S22, it is also possible to allow the temperature of the heat transfer medium to exceed the target temperature, as long as it remains below a predetermined allowable temperature. In this case, the heat exceeding the target temperature can be stored in the heat transfer medium. Therefore, in the regenerative power utilization mode, which reduces losses when utilizing regenerative power compared to charging the battery 23 before supplying power to the heat transfer medium heating device 22, if regenerative power is generated in excess of the consuming power due to transitions such as outside air introduction or dehumidification mode, allowing the temperature of the heat transfer medium to exceed the target temperature increases the amount of regenerative power consumed by the heat transfer medium heating device 22, thus allowing the heat transfer medium heating device 22 to utilize the regenerative power preferentially. Furthermore, since heating of the heat transfer medium is not required during the period until the temperature of the heat transfer medium drops to the target temperature due to the heat stored in the heat transfer medium, the power consumption of the battery 23 after the generation of regenerative power has finished can be reduced. The predetermined allowable temperature is a temperature at which occupants do not feel a change in the temperature of the air blown into the passenger compartment via the heater core 21, even if the temperature of the heat transfer medium exceeds the target temperature. In other words, the allowable temperature is a temperature range that does not impair comfort.

[0079] Furthermore, when heat is stored in the heat transfer medium in step S22, it is preferable to reduce the amount of heat dissipated from the heater core 21. Methods for reducing the amount of heat dissipated from the heater core 21 include, for example, reducing the amount of air supplied to the heater core 21 by the blower 140, reducing the amount of outside air introduced, and increasing the amount of airflow in the bypass passage 122 by driving the air mix damper 150. This allows heat to be stored in the heat transfer medium while maintaining a constant heating capacity and preventing deterioration of comfort.

[0080] Furthermore, when charging the battery 23 with regenerated power in step S22, it is preferable to allow the temperature of the heat transfer medium to exceed the target temperature within a range that remains below a predetermined allowable temperature before charging the battery 23 with regenerated power. In this case, it is preferable to heat the heat transfer medium until it reaches the allowable temperature, and then start charging the battery 23 if the temperature of the heat transfer medium exceeds the allowable temperature. This increases the amount of regenerated power consumed by the heat transfer medium heating device 22, allowing for efficient use of regenerated power. In addition, since heat can be stored in the heat transfer medium, the power consumption of the battery 23 after the generation of regenerated power can be suppressed.

[0081] The control device 200 determines whether the regenerative power supplied to the heat transfer medium heating device 22 has fallen below the target power of the heat transfer medium heating device 22 (S23).

[0082] If the control device 200 determines that the regenerative power supplied to the heat transfer medium heating device 22 is not less than or equal to the target power of the heat transfer medium heating device 22 (S23: NO), it executes the process of step S20.

[0083] The control device 200 terminates the process if it determines that the regenerative power supplied to the heat transfer medium heating device 22 has fallen below the target power of the heat transfer medium heating device 22 (S23: YES).

[0084] Subsequently, the control device 200 supplies power from the battery 23 to the heat transfer medium heating device 22 so that the temperature of the heat transfer medium remains at the target temperature. In this way, if the regenerative power supplied to the heat transfer medium heating device 22 falls below the target power of the heat transfer medium heating device 22, the control device 200 controls the temperature of the heat transfer medium so that the temperature of the heat transfer medium reaches the target temperature. As a result, heating of the heat transfer medium is not required until the temperature of the heat transfer medium reaches the target temperature due to the heat stored in the heat transfer medium, so the power consumption of the battery 23 after the generation of regenerative power is completed can be reduced. In addition, the requirement for comfort can be met by controlling the temperature of the heat transfer medium so that the temperature of the heat transfer medium reaches the target temperature.

[0085] [Relationship between heat transfer medium temperature, battery power, and regenerative power] Next, we will describe an example of the relationship between the temperature of the heat transfer medium, the battery power, and the regenerative power when the control device 200 is operating in heat storage priority mode or comfort priority mode.

[0086] <Example 1 of heat storage priority mode> Figure 5 shows an example of the relationship between the temperature of the heat transfer medium, the battery power, and the regenerative power when the heat storage priority mode is executed. In the figure, a represents the temperature of the heat transfer medium, b represents the battery power supplied from the battery 23 to the heat transfer medium heating device 22, and c represents the regenerative power supplied from the power generator 24 to the heat transfer medium heating device 22. In the figure, t1 represents the allowable temperature of the heat transfer medium, t2 represents the target temperature of the heat transfer medium, and w represents the target power, which is the power required to bring the temperature of the heat transfer medium to the target temperature. The vertical axis shows the increase or decrease of each value, and the horizontal axis shows the passage of time T.

[0087] As shown in Figure 5, when the heat transfer medium heating device 22 operates due to the supply of battery power b and the heat transfer medium is heated, the temperature a of the heat transfer medium rises. As the temperature a of the heat transfer medium rises, the battery power b supplied to the heat transfer medium heating device 22 is reduced.

[0088] Suppose that when time T1 arrives, regenerative power c is generated, and the temperature a of the heat transfer medium reaches the target temperature t2. In this case, the temperature a of the heat transfer medium is maintained at the target temperature t2 by supplying regenerative power c to the heat transfer medium heating device 22 while decreasing the battery power b supplied to the heat transfer medium heating device 22.

[0089] If the regenerated power c exceeds the target power w at time T2, the system switches to a heat storage priority mode while operating the heat transfer medium heating device 22 using only the regenerated power c, allowing the temperature a of the heat transfer medium to exceed the target temperature t2 within a range below the allowable temperature t1. This allows the heat generated when the regenerated power c exceeds the target power w to be stored in the heat transfer medium. At this time, it is preferable to lower the temperature of the air flowing to the heater core 21 or increase the air flowing to the bypass passage 122. This makes it possible to raise the allowable temperature while preventing a deterioration in comfort, and thus increases the amount of heat that can be stored.

[0090] Assume that the regenerative power c peaked out and began to decrease before time T3. Then, between time T3 and T4, the regenerative power c falls below the target power w, and the supply of regenerative power c ends after time T4. Consequently, assume that the temperature a of the heat transfer medium begins to decrease after time T3.

[0091] In this state, the heat stored in the heat transfer medium keeps the temperature a of the heat transfer medium above the target temperature t2 during the period from time T3 to time T5. Therefore, there is no need to heat the heat transfer medium with the heat transfer medium heating device 22, and thus there is no need to supply power to the heat transfer medium heating device 22. As a result, the consumption of battery power b can be reduced.

[0092] Suppose that at time T5, the temperature a of the heat transfer medium begins to fall below the target temperature t2. In this case, at time T5, the supply of battery power b to the heat transfer medium heating device 22 is resumed. At this time, battery power b is supplied so that it equals the target power w. This allows the temperature a of the heat transfer medium to be maintained at the target temperature.

[0093] <Example 2 of heat storage priority mode> Figure 6 shows an example of the relationship between the temperature of the heat transfer medium, the battery power, and the regenerative power when the heat storage priority mode is executed. In the figure, a represents the temperature of the heat transfer medium, b represents the battery power supplied from the battery 23 to the heat transfer medium heating device 22, and c represents the regenerative power supplied from the power generator 24 to the heat transfer medium heating device 22. In the figure, t1 represents the allowable temperature of the heat transfer medium, t2 represents the target temperature of the heat transfer medium, and w represents the target power, which is the power required to bring the temperature of the heat transfer medium to the target temperature. The vertical axis shows the increase or decrease of each value, and the horizontal axis shows the passage of time T.

[0094] As shown in Figure 6, when the heat transfer medium heating device 22 operates due to the supply of battery power b and the heat transfer medium is heated, the temperature a of the heat transfer medium rises. As the temperature a of the heat transfer medium rises, the battery power b supplied to the heat transfer medium heating device 22 is reduced.

[0095] Suppose that when time T1 arrives, regenerative power c is generated, and the temperature a of the heat transfer medium reaches the target temperature t2. In this case, the temperature a of the heat transfer medium is maintained at the target temperature t2 by supplying regenerative power c to the heat transfer medium heating device 22 while decreasing the battery power b supplied to the heat transfer medium heating device 22.

[0096] If the regenerated power c exceeds the target power w at time T2, the system switches to a heat storage priority mode while operating the heat transfer medium heating device 22 using only the regenerated power c, allowing the temperature a of the heat transfer medium to exceed the target temperature t2 within a range below the allowable temperature t1. This allows the heat generated when the regenerated power c exceeds the target power w to be stored in the heat transfer medium. At this time, it is preferable to lower the temperature of the air flowing to the heater core 21 or increase the air flowing to the bypass passage 122. This makes it possible to raise the allowable temperature while preventing a deterioration in comfort, and thus increases the amount of heat that can be stored.

[0097] Assume that at time T3, the temperature a of the heat transfer medium reaches or exceeds the allowable temperature t1. That is, assume that the regenerated power c exceeds the allowable power. In this case, as shown by the dotted line in the figure, there is a risk that the temperature a of the heat transfer medium will exceed the allowable temperature t1. Therefore, the system switches to comfort maintenance mode and increases the heat dissipation of the heater core 21. This consumes the power exceeding the allowable power, preventing the temperature a of the heat transfer medium from exceeding the allowable temperature.

[0098] Assume that the regenerative power c peaked out and began to decrease before time T4. Then, between time T4 and time T5, the regenerative power c falls below the target power w, and the supply of regenerative power c ends after time T4. Consequently, assume that the temperature a of the heat transfer medium begins to decrease after time T5.

[0099] In this state, the heat stored in the heat transfer medium keeps the temperature a of the heat transfer medium above the target temperature t2 during the period from time T5 to time T6. Therefore, there is no need to heat the heat transfer medium with the heat transfer medium heating device 22, and thus there is no need to supply power to the heat transfer medium heating device 22. As a result, the consumption of battery power b can be reduced.

[0100] Suppose that at time T6, the temperature a of the heat transfer medium begins to fall below the target temperature t2. In this case, at time T5, the supply of battery power b to the heat transfer medium heating device 22 is resumed. At this time, battery power b is supplied so that it reaches the target power w. This allows the temperature a of the heat transfer medium to be maintained at the target temperature.

[0101] <Example 1 of comfort-priority mode> Figure 7 shows an example of the relationship between the temperature of the heat transfer medium, battery power, and regenerative power when comfort-prioritizing mode is executed. In the figure, a represents the temperature of the heat transfer medium, b represents the battery power supplied from battery 23 to the heat transfer medium heating device 22, c represents the regenerative power supplied from power generator 24 to the heat transfer medium heating device 22, and d represents the amount of outside air introduced. In addition, t1 represents the allowable temperature of the heat transfer medium, t2 represents the target temperature of the heat transfer medium, and w represents the target power, which is the power required to bring the temperature of the heat transfer medium to the target temperature. The vertical axis shows the increase or decrease of each value, and the horizontal axis shows the passage of time T.

[0102] As shown in Figure 7, when the heat transfer medium heating device 22 operates due to the supply of battery power b and the heat transfer medium is heated, the temperature a of the heat transfer medium rises. As the temperature a of the heat transfer medium rises, the battery power b supplied to the heat transfer medium heating device 22 is reduced.

[0103] Assume that the temperature a of the heat transfer medium reaches the target temperature t2 before time T1. If the temperature a of the heat transfer medium reaches the target temperature t2, the supply of battery power b to the heat transfer medium heating device 22 is stopped. Assume that when time T1 arrives, regenerative power c is generated while the temperature a of the heat transfer medium remains at the target temperature t2.

[0104] Then, let's assume that at time T2, the regenerated power c exceeds the target power w. In this case, as shown by the dotted line in the figure, the temperature a of the heat transfer medium may exceed the target temperature t2. Therefore, while operating the heat transfer medium heating device 22 using only the regenerated power c, we switch to comfort priority mode and increase the amount of outside air introduced d to lower the temperature of the air flowing into the heater core 21. At this time, instead of increasing the amount of outside air introduced d, we may switch to dehumidification mode. As a result, the amount of heat dissipated by the heater core 21 increases, so that the power exceeding the target power can be consumed by the heat transfer medium heating device 22. This prevents the temperature a of the heat transfer medium from exceeding the target temperature.

[0105] Assume that the regenerative power c peaked out and began to decrease before time T3. Then, assume that at time T3, the regenerative power c falls below the target power w, and the supply of regenerative power c ends from time T4 onward. In this case, since the temperature a of the heat transfer medium began to fall below the target temperature t2 at time T3, the amount of outside air introduced d is returned to the amount before time T2. This suppresses heat dissipation from the heat transfer medium and maintains the temperature a of the heat transfer medium at the target temperature t2. If the temperature a of the heat transfer medium falls below the target temperature t2 after time T4, the supply of battery power b to the heat transfer medium heating device 22 is restarted to supply battery power b so that the power reaches the target power w. This maintains the temperature a of the heat transfer medium at the target temperature.

[0106] <Example 2 of Comfort Priority Mode> Figure 8 shows an example of the relationship between the temperature of the heat transfer medium, battery power, and regenerative power when comfort-prioritizing mode is executed. In the figure, a is the temperature of the heat transfer medium, b is the battery power supplied from battery 23 to the heat transfer medium heating device 22, c is the regenerative power supplied from power generator 24 to the heat transfer medium heating device 22, d is the amount of outside air introduced, and e is the power charged to battery 23. In the figure, w is the target power, which is the power required to bring the temperature of the heat transfer medium to the target temperature, t1 is the allowable temperature of the heat transfer medium, t2 is the target temperature of the heat transfer medium, and pth is the surplus threshold for determining whether the regenerative power generated exceeds the regenerative power required to maintain the temperature a of the heat transfer medium at the target temperature t2. The vertical axis shows the increase or decrease of each value, and the horizontal axis shows the passage of time T.

[0107] As shown in Figure 8, when the heat transfer medium heating device 22 operates due to the supply of battery power b and the heat transfer medium is heated, the temperature a of the heat transfer medium rises. As the temperature a of the heat transfer medium rises, the battery power b supplied to the heat transfer medium heating device 22 is reduced.

[0108] Assume that the temperature a of the heat transfer medium reaches the target temperature t2 before time T1. If the temperature a of the heat transfer medium reaches the target temperature t2, the supply of battery power b to the heat transfer medium heating device 22 is stopped. Assume that when time T1 arrives, regenerative power c is generated while the temperature a of the heat transfer medium remains at the target temperature t2.

[0109] On the other hand, suppose that at time T2 the regenerated power c exceeds the target power w. In this case, the temperature a of the heat transfer medium may exceed the target temperature t2. Therefore, while operating the heat transfer medium heating device 22 using only the regenerated power c, the system switches to comfort priority mode and increases the amount of outside air introduced d to lower the temperature of the air flowing into the heater core 21. At this time, instead of increasing the amount of outside air introduced d, the system may switch to dehumidification mode. As a result, the amount of heat dissipated by the heater core 21 increases, so that the power exceeding the target power w can be consumed by the heat transfer medium heating device 22. This prevents the temperature a of the heat transfer medium from exceeding the target temperature t2.

[0110] Then, assume that the regenerated power c exceeds the surplus threshold pth during the period T3 to T4. In this case, in order to maintain the temperature a of the heat transfer medium at the target temperature t2, the surplus power e is charged to the battery 23 during the period T3 to T4.

[0111] Assume that the regenerative power c peaked out and began to decrease before time T4. Then, at time T5, the regenerative power c falls below the target power w, and the supply of regenerative power c ends from time T6 onward. In this case, at time T5, the temperature a of the heat transfer medium begins to fall below the target temperature t2, so the amount of outside air introduced d is returned to the amount before time T2. This suppresses heat dissipation from the heat transfer medium and maintains the temperature a of the heat transfer medium at the target temperature t2. If the temperature a of the heat transfer medium falls below the target temperature t2 from time T6 onward, the supply of battery power b to the heat transfer medium heating device 22 is restarted to supply battery power b so that the power reaches the target power w. This maintains the temperature a of the heat transfer medium at the target temperature.

[0112] <Example 3 of Comfort Priority Mode> Figure 9 shows an example of the comfort-prioritizing mode. In the figure, a is the temperature of the heat transfer medium, b is the battery power supplied from the battery 23 to the heat transfer medium heating device 22, c is the regenerative power supplied from the power generator 24 to the heat transfer medium heating device 22, and d is the amount of outside air introduced. Also, t1 is the allowable temperature of the heat transfer medium, t2 is the target temperature of the heat transfer medium, w is the target power which is the power required to bring the temperature of the heat transfer medium to the target temperature, and pth is the surplus threshold for determining whether the regenerative power generated exceeds the regenerative power required to maintain the temperature a of the heat transfer medium at the target temperature t2. The vertical axis shows the increase or decrease of each value, and the horizontal axis shows the passage of time T.

[0113] As shown in Figure 9, when the heat transfer medium heating device 22 operates due to the supply of battery power b and the heat transfer medium is heated, the temperature a of the heat transfer medium rises. As the temperature a of the heat transfer medium rises, the battery power b supplied to the heat transfer medium heating device 22 is reduced.

[0114] Assume that the temperature a of the heat transfer medium reaches the target temperature t2 before time T1. If the temperature a of the heat transfer medium reaches the target temperature t2, the supply of battery power b to the heat transfer medium heating device 22 is stopped. Assume that when time T1 arrives, regenerative power c is generated while the temperature a of the heat transfer medium remains at the target temperature t2.

[0115] Then, let's assume that at time T2, the regenerated power c exceeds the target power w. In this case, there is a risk that the temperature a of the heat transfer medium will exceed the target temperature t2. Therefore, while operating the heat transfer medium heating device 22 using only the regenerated power c, we switch to comfort priority mode and increase the amount of outside air introduced d. At this time, instead of increasing the amount of outside air introduced d, we may switch to dehumidification mode. As a result, the amount of heat dissipated by the heater core 21 increases, so that the power exceeding the target power w can be consumed by the heat transfer medium heating device 22. This prevents the temperature a of the heat transfer medium from exceeding the target temperature t2.

[0116] Let's assume that the regenerated power c exceeds the surplus threshold pth during the period T3 to T4. In this case, during the period T3 to T4, the temperature a of the heat transfer medium is allowed to exceed the target temperature t2, but within the range of the allowable temperature t1 or less. Therefore, the heat generated when the regenerated power c exceeds the target power w can be stored in the heat transfer medium. The dotted line in the figure shows the change in the temperature a of the heat transfer medium when the regenerated power c does not exceed the surplus threshold pth.

[0117] Assume that the regenerative power c peaked out and began to decrease before time T4. Then, assume that at time T5, the regenerative power c falls below the target power w, and the supply of regenerative power c ends from time T6 onward. In this case, since the temperature a of the heat transfer medium began to decrease at time T5, the amount of outside air introduced d is returned to the amount before time T2. This suppresses heat dissipation from the heat transfer medium and extends the period until the temperature a of the heat transfer medium falls below the target temperature t2. If the temperature a of the heat transfer medium falls below the target temperature after time T6, the supply of battery power b to the heat transfer medium heating device 22 is restarted to supply battery power b so that the power reaches the target power w. This allows the temperature a of the heat transfer medium to be maintained at the target temperature.

[0118] [Effects of this embodiment] (a1) Battery 23 and A power generation device 24 capable of generating regenerative power, A heat transfer medium circuit 20 in which a heat transfer medium circulates to regulate the temperature of the air supplied to the vehicle interior, A vehicle air conditioning system 1 comprising a heat transfer medium heating device 22 for heating a heat transfer medium, If regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22. If the regenerative power supplied to the heat transfer medium heating device 22 exceeds the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium, the temperature of the heat transfer medium is allowed to exceed the target temperature, as long as it does not exceed a predetermined allowable temperature. Therefore, by allowing the temperature of the heat transfer medium to exceed the target temperature within a range that does not impair comfort, the consumption of regenerative power in the heat transfer medium heating device 22 increases, allowing the regenerative power to be preferentially used in the heat transfer medium heating device 22. This reduces the loss when using regenerative power compared to charging the battery 23 first.

[0119] (a2) If the regenerative power supplied to the heat transfer medium heating device 22 falls below the target power of the heat transfer medium heating device 22, the temperature of the heat transfer medium is controlled so that the temperature of the heat transfer medium reaches the target temperature. Therefore, by controlling the temperature of the heat transfer medium so that it reaches the target temperature, the requirements for comfort can be met, and since heating of the heat transfer medium is not required until the heat stored in the heat transfer medium reaches the target temperature, the power consumption of the battery 23 after the generation of regenerative power is completed can be reduced.

[0120] (b1) Battery 23 and A power generation device 24 capable of generating regenerative power, A heat transfer medium circuit 20 through which a heat transfer medium circulates to regulate the temperature of the air supplied to the vehicle interior by the heater core 21, A vehicle air conditioning system 1 comprising a heat transfer medium heating device 22 for heating a heat transfer medium, If regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22. If the regenerative power supplied to the heat transfer medium heating device 22 exceeds the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium, the temperature of the heat transfer medium is allowed to exceed the target temperature within a range that does not exceed a predetermined allowable temperature. If the regenerative power supplied to the heat transfer medium heating device 22 exceeds the allowable power of the heat transfer medium heating device 22 based on the allowable temperature, the system switches to a comfort maintenance mode that maintains the temperature of the air supplied to the passenger compartment by increasing the amount of heat dissipated from the heat transfer medium in the heater core 21. Therefore, by switching to comfort maintenance mode when the heat output of the heat transfer medium heater 22 exceeds a range that does not impair comfort, comfort can be maintained while consuming the regenerated power in the heat transfer medium heater 22 without wasting it. This reduces the loss when using regenerated power compared to charging the battery 23 once.

[0121] (b2) When switching to comfort maintenance mode, the temperature of the air flowing into the heater core 21 is reduced. Therefore, even if the temperature of the heat transfer medium rises, it becomes possible to lower the temperature of the air passing through the heater core 21, thereby maintaining the outlet temperature.

[0122] By increasing the amount of outside air introduced, the temperature of the air flowing into the heater core 21 is reduced. Therefore, ventilation can be performed, which can lower the CO2 concentration inside the vehicle.

[0123] (b3) The temperature of the air flowing into the heater core 21 is reduced by switching the air conditioning mode to dehumidification mode. Therefore, since dehumidification can be performed, fogging of the car's interior windows can be suppressed.

[0124] (c1) Battery 23 and, A power generation device 24 capable of generating regenerative power, A heat transfer medium circuit 20 through which a heat transfer medium circulates to regulate the temperature of the air supplied to the vehicle interior by the heater core 21, A vehicle air conditioning system 1 comprising a heat transfer medium heating device 22 for heating a heat transfer medium, If regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22. If the regenerative power supplied to the heat transfer medium heating device 22 exceeds the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium, the amount of heat dissipated from the heat transfer medium by the heater core 21 is increased by lowering the temperature of the air flowing into the heater core 21. Therefore, regenerative power can be consumed efficiently by the heat transfer medium heating device 22 without compromising comfort. This reduces losses when utilizing regenerative power compared to charging the battery 23 first.

[0125] (c2) The temperature of the air flowing into the heater core 21 is reduced by increasing the amount of outside air introduced. Therefore, ventilation can be performed, which can lower the CO2 concentration inside the vehicle.

[0126] (c3) By switching the air conditioning mode to dehumidification mode, the temperature of the air flowing into the heater core 21 is reduced. Therefore, since dehumidification can be performed, fogging of the car's interior windows can be suppressed.

[0127] (d1) Battery 23 and A power generation device 24 capable of generating regenerative power, A heat transfer medium circuit 20 through which a heat transfer medium circulates to regulate the temperature of the air supplied to the vehicle interior by the heater core 21, A vehicle air conditioning system 1 comprising a heat transfer medium heating device 22 for heating a heat transfer medium, If regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22. If the regenerative power supplied to the heat transfer medium heating device 22 exceeds the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium, the amount of heat dissipated from the heat transfer medium by the heater core 21 is increased by lowering the temperature of the air flowing into the heater core 21. If the regenerative power supplied to the heat transfer medium heating device 22 exceeds a predetermined surplus threshold, the regenerative power exceeding the surplus threshold is used to charge the battery 23. Therefore, in the regenerative power utilization mode, which reduces losses when utilizing regenerative power compared to charging the battery 23 before supplying power to the heat transfer medium heating device 22, if more regenerative power is generated than the power that can be consumed due to external air intake or transition to dehumidification mode, the regenerative power can be effectively utilized without being wasted by supplying power to the battery 23.

[0128] (d2) Before charging the battery 23 with regenerative power, the temperature of the heat transfer medium is allowed to exceed the target temperature, but not exceeding a predetermined allowable temperature. Therefore, the amount of regenerative power consumed by the heat transfer medium heating device 22 can be increased, and the regenerative power can be used efficiently. In addition, since heat can be stored in the heat transfer medium, the power consumption of the battery 23 after the generation of regenerative power can be suppressed.

[0129] (e1) Battery 23 and, A power generation device 24 capable of generating regenerative power, A heat transfer medium circuit 20 through which a heat transfer medium circulates to regulate the temperature of the air supplied to the vehicle interior by the heater core 21, A vehicle air conditioning system 1 comprising a heat transfer medium heating device 22 for heating a heat transfer medium, If regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22. If the regenerative power supplied to the heat transfer medium heating device 22 exceeds the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium, the amount of heat dissipated from the heat transfer medium in the heater core is increased by lowering the temperature of the air flowing into the heater core. If the regenerative power supplied to the heat transfer medium heating device 22 exceeds a predetermined surplus threshold, the temperature of the heat transfer medium is allowed to exceed the target temperature, as long as it does not exceed a predetermined allowable temperature. Therefore, in the regenerative power utilization mode, which reduces losses when utilizing regenerative power compared to charging the battery 23 before supplying power to the heat transfer medium heating device 22, if regenerative power is generated in excess of the available power due to external air intake or transition to dehumidification mode, allowing the temperature of the heat transfer medium to exceed the target temperature increases the amount of regenerative power consumed by the heat transfer medium heating device 22, thus allowing the regenerative power to be preferentially utilized by the heat transfer medium heating device 22. In addition, since heating of the heat transfer medium is not required until the temperature of the heat transfer medium reaches the target temperature due to the heat stored in the heat transfer medium, the power consumption of the battery 23 after the generation of regenerative power has finished can be reduced.

[0130] (f1) Battery 23, A power generation device 24 capable of generating regenerative power, A heat transfer medium circuit 20 through which a heat transfer medium circulates to regulate the temperature of the air supplied to the vehicle interior by the heater core 21, A vehicle air conditioning system 1 comprising a heat transfer medium heating device 22 for heating a heat transfer medium, If regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22. If the regenerative power supplied to the heat transfer medium heating device 22 exceeds the target power of the heat transfer medium heating device 22 based on the target temperature of the heat transfer medium, it is possible to select and execute either a comfort-priority mode, which increases the amount of heat dissipated from the heat transfer medium in the heater core 21 so that the temperature of the heat transfer medium becomes the target temperature based on the target blown air temperature supplied to the vehicle interior, or a heat storage-priority mode, which increases the amount of heat dissipated from the heat transfer medium in the heater core 21 while allowing the temperature of the heat transfer medium to exceed the target temperature within a range that does not exceed a predetermined allowable temperature. Therefore, in the regenerative power utilization mode, which reduces losses when utilizing regenerative power compared to charging with the battery 23 before supplying power to the heat transfer medium heating device 22, it is possible to switch between a comfort-priority mode, which increases the amount of heat dissipated from the heat transfer medium in the heater core 21 to keep the temperature of the heat transfer medium constant, and uses the increased amount of heat dissipation to increase the amount of outside air introduced or to switch to a dehumidification mode, thereby contributing to improved comfort, and a heat storage-priority mode, which allows the temperature of the heat transfer medium to exceed the target temperature to keep the outlet temperature constant while storing heat in the heat transfer medium, thus enabling efficient use of surplus regenerative power.

[0131] (f2) The control device 200 is provided as a storage unit that stores information indicating the selection history of comfort priority mode and heat storage priority mode, and information indicating the environment when comfort priority mode or heat storage priority mode is selected. Based on the information stored in the control device 200, it selects whether to recommend the comfort-priority mode or the heat storage-priority mode. Therefore, occupants only need to select the recommended mode, preventing them from feeling inconvenienced by having to choose between comfort-priority mode and heat-storage-priority mode.

[0132] (f3) Equipped with a control device 200 as an acquisition unit that acquires information indicating the air quality inside and outside the vehicle, If the air quality outside the vehicle is better than the air quality inside the vehicle, the heat storage priority mode will be prioritized. Therefore, when the air quality outside the vehicle is good, it is possible to actively take in outside air, and when the air quality outside the vehicle is poor, it is possible to refrain from taking in outside air, thus improving comfort.

[0133] (f4) If the difference between the temperature of the heat transfer medium and the predetermined allowable upper temperature limit falls below a predetermined level while the heat storage priority mode is running, the comfort priority mode will be prioritized. Therefore, by excessively storing heat, it is possible to suppress the occurrence of malfunctions in the heat transfer medium circuit 20.

[0134] Although the present invention has been described above with reference to preferred embodiments, it goes without saying that the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the present invention. [Explanation of Symbols]

[0135] 1: Vehicle air conditioning system 20: Heat medium circuit 30: Refrigerant Circuit 21: Heater core 31: Coola Core 200: Control device 210: Heat transfer medium temperature sensor

Claims

1. Battery and A power generation device capable of generating regenerative power, A heat transfer medium circuit in which a heat transfer medium circulates to regulate the temperature of the air supplied to the vehicle interior using a heater core, A vehicle air conditioning system comprising a heat transfer medium heating device for heating a heat transfer medium, If regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device. If the regenerative power supplied to the heat transfer medium heating device exceeds the target power of the heat transfer medium heating device based on the target temperature of the heat transfer medium, the amount of heat dissipated from the heat transfer medium in the heater core is increased by lowering the temperature of the air flowing into the heater core. A vehicle air conditioning system characterized by the following features.

2. By increasing the amount of outside air introduced, the temperature of the air flowing into the heater core is reduced. The vehicle air conditioning system according to feature 1.

3. Switching the air conditioning mode to dehumidification mode lowers the temperature of the air flowing into the heater core. The vehicle air conditioning system according to feature 1.

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