Vehicle air conditioning device

Abstract

[Problem] To provide a vehicle air conditioning device capable of utilizing surplus regenerative electric power without waste. [Solution] According to the present invention, when regenerative electric power is generated while a space heating operation is being performed, the regenerative electric power is supplied to a heat medium heating device 22, and if the regenerative electric power supplied to the heat medium heating device 22 exceeds a target electric power of the heat medium heating device 22 based on a target temperature of the heat medium, it is possible to select and execute either a comfort priority mode in which the amount of heat dissipated by the heat medium in a heater core 21 is increased such that the temperature of the heat medium becomes a target temperature based on a target blowing temperature of air supplied into the vehicle cabin interior, or a heat storage priority mode in which the amount of heat dissipated by the heat medium in the heater core 21 is increased by allowing the temperature of the heat medium to exceed the target temperature within a range not exceeding a predetermined allowable temperature.

Description

Vehicle air conditioner

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

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

[0003] U.S. Patent No. 10,036,288 Specification of Chinese Patent No. 11,314,7321

[0004] An object of the present invention is to provide a vehicle air conditioner that can utilize surplus regenerative power without waste.

[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, a comfort priority mode in which the heat dissipation amount of the heat medium in the heater core is increased so that the temperature of the heat medium becomes the target temperature based on the target blowing temperature of the air supplied into the vehicle interior, and a heat storage priority mode in which the heat dissipation amount of the heat medium in the heater core is increased while allowing the temperature of the heat medium to exceed the target temperature within a range not exceeding a predetermined allowable temperature can be selected and executed.

[0006] According to the present invention, a vehicle air conditioner that can utilize surplus regenerative power without waste can be provided.

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

[0008] [Configuration of the Vehicle Air Conditioning System] <Overview of the Vehicle Air Conditioning System> Figure 1 is an explanatory diagram showing a schematic of the 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] <Heat Transfer 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 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 switches 25a, 25b, and 25c. Switch 25a switches the connection or disconnection between the power generator 24 and the heat transfer medium heating device 22. Switch 25b switches the connection or disconnection between the battery 23 and the heat transfer medium heating device 22. Switch 25c switches the connection or disconnection between the battery 23 and the power generator 24.

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

[0014] <Refrigerant Circuit> In the refrigerant circuit 30, a refrigerant such as hydrofluoroolefin circulates. The refrigerant circuit 30 functions as a heat pump that circulates the refrigerant and repeatedly compresses, condenses, expands, and evaporates it. The refrigerant circuit 30 comprises a cooler core 31, an outdoor heat exchanger 32, a compressor 33, and a pressure reducing device 34. The compressor 33 compresses the gaseous refrigerant to high temperature and pressure before discharging it. The outdoor heat exchanger 32 condenses the compressed gaseous refrigerant to release heat. The pressure reducing device 34 expands the liquid refrigerant to low pressure. The cooler core 31 evaporates the liquid refrigerant, which has been reduced to low temperature and low pressure, to absorb heat. The refrigerant circuit 30 can be used to cool or dehumidify the interior of a vehicle by operating the cooler core 31.

[0015] <HVAC Unit> The heater core 21 of the heat transfer medium circuit 20 and the cooler core 31 of the refrigerant circuit 30 are housed within the case 110 of the HVAC unit 100. The case 110 forms the outer shell of the HVAC unit 100 and also forms an air passage 120 inside.

[0016] The HVAC unit 100 includes an intake unit 130. The intake unit 130 switches the air introduced into the case 110 between outside air (outside air intake) and inside air (inside air circulation) by closing either an outside air intake for introducing outside air or an inside air intake for introducing inside air. The HVAC unit 100 also 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 passage 120.

[0017] A cooler core 31 is located upstream of the airflow passage 120, and a heater core 21 is located downstream of the cooler core 31 in the airflow passage 120. Furthermore, a heater core passage 121 and a bypass passage 122 are formed in parallel downstream of the airflow passage 120. The heater core passage 121 is located downstream of the heater core 21. Therefore, when air introduced into the case 110 is directed to the heater core passage 121, the air is passed through the cooler core 31 before being passed through the heater core 21. On the other hand, when air introduced into the case 110 is directed to the bypass passage 122, the air is passed through the cooler core 31 before bypassing the heater core 21. The ratio of air passing through the heater core passage 121 to 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 (for example, 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 Vehicle Air Conditioning System 1] The specific operation of the vehicle air conditioning system 1 will be explained below. <Heating Operation> Figure 1 shows the state of the vehicle air conditioning system 1 when the air conditioning mode is set to heating operation 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] 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 processing 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 of 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] When 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, in step S4, it can be said that the control device 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 the comfort-priority mode or the heat storage-priority mode in step S5 can be made based on various methods or 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 between 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 to recommend based on the information stored by the control device 200. This prevents occupants from feeling inconvenienced by having to choose 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 minimizes fuel consumption, the system can determine that the heat storage priority mode is the occupant's preference and select that mode. Also, if the air conditioning is 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] Also, as an example of the selection method in step S5, an example of selecting the heat storage priority mode or the comfort priority mode based on the air quality inside and outside the vehicle cabin can be given.

[0045] In this case, it is preferable that the control device 20 acquires information indicating the air quality inside and outside the vehicle cabin, and gives priority to the heat storage priority mode when the air quality outside the vehicle cabin is better than that inside the vehicle cabin. Thereby, when the air quality outside the vehicle cabin is good, outside air can be actively taken in, and when the air quality outside the vehicle cabin is bad, it is possible not to take in outside air, so comfort is improved.

[0046] As a specific example, when the quality of the air outside the vehicle deteriorates beyond a certain value based on information acquired via the Internet or information directly measured, the comfort priority mode is selected, and the heat storage priority mode is selected until the quality of the air outside the vehicle exceeds a certain value. Also, an example can be given where the comfort priority mode is selected when the CO2 concentration inside the vehicle is above a certain concentration (that is, a concentration above the threshold value), and the heat storage priority mode is selected until the CO2 concentration inside the vehicle reaches a concentration above a certain level. Note that it is preferable to determine the air quality by combining a plurality of determination criteria such as, for example, humidity, CO2 concentration, dust concentration, and odor concentration.

[0047] Also, as an example of the selection method in step S5, an example of selecting the heat storage priority mode or the comfort priority mode based on the difference between the temperature of the heat medium and a predetermined allowable upper limit temperature of the heat medium can be given. The predetermined allowable upper limit temperature is, for example, a temperature at which there is a possibility of a problem occurring in the heat medium circuit 20.

[0048] In this case, it is preferable to give priority to the comfort priority mode when the difference between the temperature of the heat medium and the predetermined allowable upper limit temperature becomes less than or equal to a predetermined value during the execution of the heat storage priority mode. Thereby, it is possible to suppress the occurrence of problems in the heat medium circuit 20 by 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, even if the temperature of the heat transfer medium exceeds the target temperature, the occupants do not feel any change in the temperature of the air blown into the passenger compartment via the heater core 21. 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 amount of regenerative power consumed by the heat medium heating device 22 increases, so that the regenerative power can be preferentially used by the heat medium heating device 22. This reduces the loss when using regenerative power compared to charging the battery 23 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, there is a risk that the outlet temperature will decrease due to the decrease in the temperature of the air flowing into the heater core 21, 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, by switching the air conditioning mode to dehumidification mode (i.e., dehumidifying heating mode), the temperature of the air flowing into the heater core 21 is reduced. That is, by increasing the rotational speed of the compressor 33, the temperature of the refrigerant flowing through the cooler core 31 is reduced. As a result, the power consumption of the compressor 33 increases, 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, so surplus power can be consumed. And by reducing the temperature of the refrigerant flowing through the cooler core 31, the dehumidification capacity of the cooler core 31 can be improved. At this time, since there is a risk that the discharge temperature will decrease due to the reduction 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 the 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 the 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] In this way, the control device 200 controls the temperature of the heat medium so that it reaches the target temperature when the regenerative power supplied to the heat medium heating device 22 falls below the target power of the heat medium heating device 22. As a result, heating of the heat medium is not required until the heat medium reaches the target temperature due to the heat stored in the heat 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 medium so that it reaches the target temperature.

[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] When 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 discharge temperature within a certain range. Furthermore, in the regenerated 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 introduction 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 makes it possible to store heat 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 when 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 the 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, an example of the relationship between the heat transfer medium temperature, battery power, and regenerative power when the control device 200 is executing the heat storage priority mode or the comfort priority mode will be described.

[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. Also, 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 reaches 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. Also, 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 priority mode is implemented. 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, 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, and w is 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, the battery power, and the regenerative power when comfort priority mode is implemented. 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, d is the amount of outside air introduced, and e is the power charged to the battery 23. In addition, 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, 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, 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 from time T3 to time 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 from time T3 to time 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 when comfort priority mode is implemented. 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 from time T3 to time T4. In this case, during the period from time T3 to time T4, the temperature a of the heat transfer medium is allowed to exceed the target temperature t2 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, 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) A vehicle air conditioning system 1 comprising a battery 23, a power generation device 24 capable of generating regenerative power, a heat transfer medium circuit 20 through which a heat transfer medium that adjusts the temperature of the air supplied to the vehicle interior circulates, and a heat transfer medium heating device 22 that heats the heat transfer medium, wherein when regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22, and 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. Therefore, by allowing the temperature of the heat transfer medium to exceed the target temperature within a range that does not impair comfort, the amount of regenerative power consumed by the heat transfer medium heating device 22 increases, so that the regenerative power can be preferentially used by the heat transfer medium heating device 22. As a result, the loss when using regenerative power can be reduced compared to charging the battery 23 with the regenerative power once.

[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 the temperature of the heat transfer medium reaches the target temperature, the requirements for comfort are met, and 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 is completed can be reduced.

[0120] (b1) A vehicle air conditioning system 1 comprising a battery 23, a power generator 24 capable of generating regenerative power, a heat transfer medium circuit 20 through which a heat transfer medium circulates to adjust the temperature of the air supplied to the vehicle interior by a heater core 21, and a heat transfer medium heating device 22 for heating the heat transfer medium, wherein when regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22, and 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, and 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 in which the amount of heat dissipated by the heat transfer medium in the heater core 21 is increased to maintain the blown air temperature supplied to the vehicle interior. 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 is possible to reduce 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 reduce the CO2 concentration inside the vehicle.

[0123] (b3) By switching the air conditioning mode to dehumidification mode, the temperature of the air flowing into the heater core 21 is reduced. Therefore, dehumidification can be performed, which can suppress fogging of the windows in the vehicle interior.

[0124] (c1) A vehicle air conditioning system 1 comprising a battery 23, a power generator 24 capable of generating regenerative power, a heat transfer medium circuit 20 through which a heat transfer medium circulates to adjust the temperature of the air supplied to the vehicle interior by a heater core 21, and a heat transfer medium heating device 22 for heating the heat transfer medium. 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 by the heat transfer medium in 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 using regenerative power compared to charging the battery 23 once.

[0125] (c2) 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, and the CO2 concentration inside the vehicle can be reduced.

[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, dehumidification can be performed, which can suppress fogging of the windows in the vehicle interior.

[0127] (d1) A vehicle air conditioning system 1 comprising a battery 23, a power generator 24 capable of generating regenerative power, a heat transfer medium circuit 20 through which a heat transfer medium circulates to adjust the temperature of the air supplied to the vehicle interior by a heater core 21, and a heat transfer medium heating device 22 for heating the heat transfer medium, wherein when regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22, and 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 by the heat transfer medium in the heater core 21 is increased by lowering the temperature of the air flowing into the heater core 21, and if the regenerative power supplied to the heat transfer medium heating device 22 is equal to or greater than a predetermined surplus threshold, the regenerative power exceeding the surplus threshold is charged to 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 within a range that does not exceed 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) A vehicle air conditioning system 1 comprising a battery 23, a power generator 24 capable of generating regenerative power, a heat transfer medium circuit 20 through which a heat transfer medium circulates to adjust the temperature of the air supplied to the vehicle interior by a heater core 21, and a heat transfer medium heating device 22 for heating the heat transfer medium, wherein when regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device 22, and 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 by the heat transfer medium in the heater core is increased by lowering the temperature of the air flowing into the heater core, and if the regenerative power supplied to the heat transfer medium heating device 22 is equal to or greater than a predetermined surplus threshold, 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. 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) A vehicle air conditioning system 1 comprising a battery 23, a power generator 24 capable of generating regenerative power, a heat transfer medium circuit 20 through which a heat transfer medium circulates to adjust the temperature of the air supplied to the vehicle interior by a heater core 21, and a heat transfer medium heating device 22 for heating the heat transfer medium. When regenerative power is generated during heating operation, the system supplies the regenerative power 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 system can select and execute either a comfort-priority mode, which increases the amount of heat dissipated from the heat transfer medium by the heater core 21 so that the temperature of the heat transfer medium becomes a target temperature based on the target outlet temperature of the air supplied to the vehicle interior, or a heat storage-priority mode, which allows the temperature of the heat transfer medium to exceed the target temperature within a range that does not exceed a predetermined allowable temperature, and increases the amount of heat dissipated from the heat transfer medium by the heater core 21. 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 system includes a control device 200 as a memory unit that stores information indicating the selection history between 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. Based on the information stored by the control device 200, the system selects which of the comfort priority mode and heat storage priority mode to recommend. Therefore, the occupants only need to select the recommended mode, thus preventing them from feeling inconvenienced by having to choose between comfort priority mode and heat storage priority mode.

[0132] (f3) The vehicle is equipped with a control device 200 as an acquisition unit that acquires information indicating the air quality inside and outside the vehicle, and prioritizes the heat storage priority mode when the air quality outside the vehicle is better than the air quality inside the vehicle. Therefore, when the air quality outside the vehicle is good, outside air is actively taken in, and when the air quality outside the vehicle is poor, outside air is not taken in, thus improving comfort.

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

[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.

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

Claims

1. A vehicle air conditioning system comprising a battery, a power generation device capable of generating regenerative power, a heat transfer medium circuit through which a heat transfer medium circulates to regulate the temperature of air supplied to the vehicle cabin by a heater core, and a heat transfer medium heating device for heating the heat transfer medium, wherein when regenerative power is generated during heating operation, the regenerative power is supplied to the heat transfer medium heating device, and 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 system is capable of selecting and executing either a comfort-priority mode, which increases the amount of heat dissipated from the heat transfer medium in the heater core so that the temperature of the heat transfer medium becomes a target temperature based on the target outlet temperature of the air supplied to the vehicle cabin, or a heat storage-priority mode, which increases the amount of heat dissipated from the heat transfer medium in the heater core 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.

2. The vehicle air conditioning system according to claim 1, comprising a storage unit that stores information indicating the selection history of the comfort priority mode and the heat storage priority mode, and information indicating the environment when the comfort priority mode or the heat storage priority mode is selected, wherein the storage unit selects which of the comfort priority mode and the heat storage priority mode to recommend based on the information stored in the storage unit.

3. The vehicle air conditioning system according to claim 1, comprising an acquisition unit that acquires information indicating the air quality inside and outside the vehicle, and prioritizing the heat storage priority mode when the air quality outside the vehicle is better than the air quality inside the vehicle.

4. The vehicle air conditioning system according to claim 1, characterized in that if the difference between the temperature of the heat transfer medium and a predetermined allowable upper temperature falls below a predetermined level while the heat storage priority mode is in operation, the comfort priority mode is prioritized.

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