Vehicle air conditioning system

Abstract

To provide a vehicle air conditioning system capable of suppressing power consumption when the vehicle is in a maximum heating state during dehumidification heating with a setting in a dual mode.SOLUTION: When front and rear air conditioning units 28F, 28R are operating together under a condition in which an air conditioning system 26 is performing dehumidifying heating, upon reaching a maximum heating state (MAXHOT), the air conditioning system causes: a refrigeration cycle circuit 30 to stop; and a heating circuit 32 to produce high-temperature liquid using an electric heater 38 and to supply the high-temperature liquid to front and rear heater cores 44F, 44R.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an air conditioning device for a vehicle. [Background technology]

[0002] Patent Document 1 below discloses a vehicle air conditioner that uses a refrigeration cycle to dehumidify and heat the passenger compartment of a vehicle. An evaporator (2) and a radiator (4) are arranged in an air conditioner casing (1), which serves as a passage for air sent to the passenger compartment. When performing dehumidifying and heating, a refrigerant compressed by a compressor (7) and heated to a high temperature is sent to the radiator (4). The refrigerant is sent from the radiator (4) to an exterior heat exchanger (8) where it is cooled, and then sent to the evaporator (2). Within the air conditioner casing (1), the air is cooled by the evaporator (2), and water vapor in the air condenses. The dehumidified and cooled air is heated by the radiator (4), and the dehumidified warm air is blown into the passenger compartment. A vehicle air conditioner is also known that has separate air conditioning units for conditioning the front and rear spaces of the passenger compartment. The reference numerals in the parentheses above are the reference numerals used in the following Patent Document 1, and are not related to the reference numerals used in the description of the embodiments of the present application. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-142506 Summary of the Invention [Problem to be solved by the invention]

[0004] During dehumidifying and heating operation, the refrigerant may become two-phase gas and liquid, and may not be properly distributed between the front and rear air conditioning units. This reduces air conditioning efficiency and increases the air conditioning system's power consumption. This increases power consumption, particularly when the system is in maximum heating mode, where most of the air passing through the air conditioning units (which cool and heat the air) passes through the heater core (which heats the air). Furthermore, in vehicles equipped with electric motors for driving the vehicle, increased power consumption by the air conditioning system may shorten the vehicle's driving range.

[0005] The present invention reduces power consumption of an air conditioner when both the front and rear air conditioning units operate under dehumidifying and heating conditions and at least one of the air conditioning units operates in maximum heating mode. [Means for solving the problem]

[0006] A vehicle air conditioning system according to the present invention includes a front air conditioning unit that conditions the air of a front space of a vehicle passenger compartment, a rear air conditioning unit that conditions the air of a rear space of the vehicle passenger compartment, a refrigeration cycle circuit that supplies refrigerant to evaporators of the front air conditioning unit and the rear air conditioning unit, and a heating circuit that generates high-temperature liquid by selectively using a heat source and / or refrigerant from the refrigeration cycle circuit and supplies the high-temperature liquid to heater cores of the front air conditioning unit and the rear air conditioning unit. Furthermore, in a dehumidifying heating range determined based on a required discharge temperature that is a control target for the temperature of air discharged from the front air conditioning unit and the rear air conditioning unit and an outside air temperature, when the front air conditioning unit and the rear air conditioning unit are operating and at least one of the front air conditioning unit and the rear air conditioning unit reaches a maximum heating state in which the amount of air discharged from the air conditioning unit that has passed through the heater core is at its maximum, the vehicle air conditioning system stops operation of the refrigeration cycle circuit and performs heat-source heating operation in which the heating circuit generates high-temperature liquid by using the heat source.

[0007] In another aspect of the vehicle air conditioning device, when the front air conditioning unit and the rear air conditioning unit are in operation in a dehumidifying heating region determined based on the required blowing temperature, which is the control target for the temperature of the air discharged from the front air conditioning unit and the rear air conditioning unit, and the outside air temperature, and at least one of the front air conditioning unit and the rear air conditioning unit is in a maximum heating state in which the proportion of air that has passed through the heater core among the air discharged from the air conditioning unit is at its maximum, and a power reduction mode is selected to reduce the power consumption of the battery that supplies power to the electric motor that drives the vehicle, the operation of the refrigeration cycle circuit is stopped and a heat source heating operation is performed in which the heating circuit uses a heat source to generate high-temperature liquid.

[0008] Furthermore, in the above-described vehicle air conditioning system, the heat source of the heating circuit may be either or both of the engine that drives the vehicle and an electric heater. [Effects of the Invention]

[0009] In the dehumidifying heating area, when both the front and rear air conditioning units are operating and at least one of them is in maximum heating mode, or when a power reduction mode is selected, the operation of the refrigeration cycle circuit is stopped to reduce power consumption. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic configuration of a vehicle equipped with a thermal management system of a first embodiment. [Figure 2] FIG. 2 is a diagram showing a front air conditioning unit and its control unit. [Figure 3] 1 is a diagram illustrating a schematic configuration of a thermal management system according to a first embodiment. [Figure 4] FIG. 3 is a diagram showing conditions that define operation modes of the air conditioner of the first embodiment. [Figure 5] FIG. 2 is a diagram showing the operating state of the thermal management system of the first embodiment, particularly showing the state during heating operation using engine coolant. [Figure 6]FIG. 2 is a diagram showing an operating state of the thermal management system of the first embodiment, particularly showing a state during heating operation using an electric heater. [Figure 7] FIG. 2 is a diagram showing the operating state of the thermal management system of the first embodiment, particularly showing the state during heating operation by heat pump operation of the refrigeration cycle circuit. [Figure 8] FIG. 2 is a diagram showing an operating state of the thermal management system of the first embodiment, particularly showing a state during cooling operation. [Figure 9] FIG. 2 is a diagram showing the operating state of the thermal management system of the first embodiment, particularly showing the state during parallel dehumidifying and heating operation. [Figure 10] FIG. 2 is a diagram showing the operating state of the thermal management system of the first embodiment, particularly showing the state during serial dehumidifying and heating operation. [Figure 11] FIG. 1 is a diagram illustrating an example of a control flow of a thermal management system. [Figure 12] FIG. 10 is a diagram illustrating another example of a control flow of the thermal management system. [Figure 13] FIG. 10 is a diagram schematically illustrating the configuration of a thermal management system according to a second embodiment. [Figure 14] FIG. 10 is a diagram showing conditions that define the operation modes of an air conditioner according to a second embodiment. [Figure 15] FIG. 10 is a diagram showing an operating state of the thermal management system of the second embodiment, and in particular a first example of a state during dehumidifying and heating operation. [Figure 16] FIG. 10 is a diagram showing an operating state of the thermal management system of the second embodiment, and in particular a second example of a state during dehumidifying and heating operation. [Figure 17] FIG. 10 is a diagram showing an operating state of the thermal management system of the second embodiment, and is particularly a diagram showing a third example of a state during dehumidifying and heating operation. [Figure 18] FIG. 10 is a diagram showing the operating state of the thermal management system of the second embodiment, particularly showing the state during heating operation by the heating circuit using its heat source. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the general configuration of a thermal management system 12 of a vehicle 10. The vehicle 10 is equipped with an engine 14 and two electric motors 16F, 16R that drive the front and rear wheels, respectively, as prime movers for driving the vehicle 10. The vehicle 10 is equipped with a battery 18 that supplies power to the electric motors 16F, 16R and is charged with electricity generated by the electric motors 16F, 16R during braking. The vehicle may be equipped with a single electric motor that drives only the front wheels or the rear wheels. Furthermore, the vehicle may be equipped with no engine and drive one or both of the front and rear wheels with an electric motor. Hereinafter, for simplicity, the electric motors 16F, 16R will be simply referred to as motor 16.

[0012] The thermal management system 12 cools the engine 14, the motor 16, and the battery 18, and also provides air conditioning for the passenger compartment 20. The cooling system for the engine 14 includes an engine radiator 22 that dissipates heat generated by the engine through engine coolant. The engine coolant flows through piping connecting the engine 14 and the engine radiator 22 and circulates between the engine 14 and the engine radiator 22. In FIG. 1, the piping connecting the engine 14 and the engine radiator 22 is omitted. The cooling system for the motor 16 includes a motor radiator 24 that dissipates heat generated by the motor 16 through motor coolant. The motor coolant flows through piping connecting the motor 16 and the motor radiator 24 and circulates between the motor 16 and the motor radiator 24. In FIG. 1, the piping connecting the motor 16 and the motor radiator 24 is omitted.

[0013] The thermal management system 12 includes an air conditioner 26 that conditions the passenger compartment 20. The air conditioner 26 has an air conditioning unit 28 that supplies air whose temperature, humidity, etc. have been regulated to the passenger compartment 20. The air conditioning unit 28 includes a front air conditioning unit 28F that conditions the front seat space of the passenger compartment 20 and a rear air conditioning unit 28R that conditions the rear seat space. The air conditioner 26 includes a refrigeration cycle circuit 30 that supplies refrigerant to the air conditioning unit 28 and a heating circuit 32 that supplies heated liquid. The refrigeration cycle circuit 30 includes a compressor 34 that compresses the refrigerant and an outdoor condenser 36 that cools the refrigerant compressed by the compressor 34 with outside air to liquefy it. The compressor 34 may be an electric compressor driven by an electric motor, and the output of the compressor 34 can be adjusted by controlling the rotational speed of the electric motor. The compressor 34 is also supplied with power from the battery 18. The heating circuit 32 includes an electric heater 38 as a heat source. The refrigeration cycle circuit 30 and the heating circuit 32, including the other cooling systems of the thermal management system 12, will be described in more detail below.

[0014] The thermal management system 12 further includes a battery cooling circuit 40 that cools the battery 18. The battery cooling circuit 40 supplies battery coolant cooled by the refrigerant of the refrigeration cycle circuit 30 in a battery cooling heat exchanger 41 to the battery 18 to cool the battery 18.

[0015] 2 is a diagram schematically illustrating the configuration of the front air conditioning unit 28F. The front air conditioning unit 28F has a front evaporator 42F, which is one of the components of the refrigeration cycle circuit 30, and a front heater core 44F, which is one of the components of the heating circuit 32, and further has an air conditioning case 46 that houses the front evaporator 42F and the front heater core 44F. The air conditioning case 46 has an air inlet 48 that introduces air into the air conditioning case 46. The air inlet 48 includes an inside air inlet 48C that introduces air from inside the passenger compartment 20 and an outside air inlet 48E that introduces air from outside the vehicle. The air conditioning case 46 also has an air outlet 50 that sends conditioned air toward a predetermined location. The air outlets 50 include a head outlet 50H that delivers airflow toward the heads and surrounding areas of front seat occupants, a foot outlet 50F that delivers airflow toward the feet of the front seat occupants, and a defroster outlet 50D that delivers airflow toward the interior surface of the windshield. The airflow delivered from the head outlet 50H passes through a duct in the instrument panel (not shown) and is blown out toward the heads and surrounding areas of the front seat occupants in the passenger compartment 20 from multiple outlets formed in the instrument panel. The airflow delivered from the foot outlet 50F is blown out toward the feet of the front seat occupants directly from the foot outlet 50F or through a duct in the instrument panel. The airflow delivered from the defroster outlet 50D passes through a duct in the instrument panel and is blown out from an outlet provided opposite the lower edge of the windshield. The front air conditioning unit 28F has a blower 52 disposed upstream of the air conditioning case 46. The blower 52 generates an air flow that flows from the air inlet 48 to the air outlet 50.

[0016] An inside / outside air switching door 54 is disposed at the confluence of the flow path from inside air inlet 48C and the flow path from outside air inlet 48E. Inside / outside air switching door 54 is rotatable between a position that closes inside air inlet 48C and a position that closes outside air inlet 48E, and the mixing ratio of inside air and outside air is adjusted according to the rotation angle.

[0017] An air mix door 56 is disposed between the front evaporator 42F and the front heater core 44F. The air mix door 56 can be rotated to a fully open position, where it directs all or most of the air passing through the front air conditioning unit 28F to the front heater core 44F, or a fully closed position, where it bypasses all or most of the air. The air mix door 56 can also be positioned at any intermediate position between the fully open and fully closed positions. When the air mix door 56 is positioned in the intermediate position, airflows that pass through the front heater core 44F and airflows that bypass the front heater core 44F are generated, and these airflows later mix together. Changing the rotational position of the air mix door 56 adjusts the ratio of air that passes through the front heater core 44F to air that bypasses the front heater core 44F, thereby adjusting the temperature of the air discharged from the front air conditioning unit 28F. In other words, the rotational position of the air mix door 56 adjusts the ratio of the air that has passed through the front heater core 44F to the air that has passed through the front air conditioning unit 28F, thereby adjusting the temperature of the air discharged from the front air conditioning unit 28F. In FIG. 2, the position of the air mix door 56 represented by the solid line is the fully open position, and the position represented by the dashed line is the fully closed position. When the air mix door 56 is in the fully open position, the temperature of the air discharged from the front air conditioning unit 28F is the highest possible temperature at that time. The state of the front air conditioning unit 28F at this time is hereinafter referred to as the maximum heating state. The maximum heating state is sometimes called the MAXHOT mode.

[0018] An outlet door 58 for opening and closing the air outlet 50 is provided corresponding to each air outlet 50. Specifically, a head outlet door 58H is provided for the head outlet 50H, a foot outlet door 58F is provided for the foot outlet 50F, and a defroster outlet door 58D is provided for the defroster outlet 50D, and the amount of air blown from each outlet 50 is adjusted by the opening degree of each outlet door 58.

[0019] The control unit 60 controls the airflow rate of the blower 52, the rotational positions of the inside / outside air switching door 54 and the air mix door 56, and the opening degrees of each outlet door 58. The control unit 60 controls the rotational angles of the inside / outside air switching door 54 and the air mix door 56, the opening degrees of each outlet door 58, and the airflow rate of the blower 52 based on conditions set by the occupant and environmental conditions. Each door 54, 56, and 58 is provided with a sensor that detects its rotational position or opening degree, and the control unit 60 determines its rotational position or opening degree based on the values ​​detected by these sensors. The occupant sets the desired interior temperature using the temperature setting switch 62 and then uses the outlet selector switch 64 to select the air outlet 50 from which they want to blow air. The air outlet 50 can be selected in a blowing mode that selects one of the air outlets 50H, 50F, and 50D individually, or in a blowing mode that blows air from both the head outlet 50H and the foot outlet 50F. The occupant can also set the automatic air conditioning mode using the automatic air conditioning switch 66. In this case, the control unit 60 selects the air outlet 50 from which to blow air according to a predetermined program in accordance with the desired temperature and environmental conditions. The control unit 60 receives inputs such as the air temperature in the passenger compartment 20 detected by a room temperature sensor 69, the outside air temperature detected by an outside air temperature sensor 70, the liquid temperature in the heating circuit 32 detected by a liquid temperature sensor 72, and the amount of solar radiation entering the passenger compartment 20 detected by a solar radiation sensor 74. The control unit 60 also receives inputs such as the temperature of the air immediately after passing through the front evaporator 42F (evaporator outlet temperature) detected by an evaporator outlet temperature sensor 76 located immediately after the front evaporator 42F.

[0020] When the occupant sets the upper limit of the settable range of the interior temperature, the air mix door 56 is fully opened and the front air conditioning unit 28F is set to maximum heating. Also, even if the set desired interior temperature is not the upper limit temperature, the front air conditioning unit 28F may be controlled to maximum heating if there is a large difference between the set desired interior temperature and the outside temperature.

[0021] The rear air conditioning unit 28R has a configuration similar to that of the front air conditioning unit 28F and is not shown in the drawings. The rear air conditioning unit 28R has an air conditioning case that houses the rear evaporator 42R and the rear heater core 44R (see FIG. 1), and the air conditioning case is provided with an air inlet and an air outlet. In the rear air conditioning unit 28R, the air inlet does not need to include an outside air inlet, and the air outlet does not need to include a defroster outlet. Like the front air conditioning unit 28F, the rear air conditioning unit 28R can send conditioned air to either the heads or the areas around them and / or the feet of rear seat occupants.

[0022] The rear air conditioning unit 28R can be switched on and off by the passenger. When the passenger operates the rear air conditioning switch 67, the control unit 60 operates the rear air conditioning unit 28R in addition to the front air conditioning unit 28F. The front air conditioning unit 28F and the rear air conditioning unit 28R can be independently set to different temperatures and have different air outlet modes. In addition, a power reduction switch 68 is provided to set a power reduction mode, also known as an energy saving mode or eco mode, for reducing power consumption by the thermal management system 12. When the power reduction switch 68 is operated, the control unit 60 controls the thermal management system 12 to reduce power consumption. For example, the control unit 60 sets an upper limit for the output of the compressor 34 that is lower than the maximum output, and controls the compressor 34 to operate at or below this upper limit output.

[0023] The control unit 60 is a processing device that controls the air conditioning device 26 in accordance with a predetermined program, and operates to realize the temperature and air blowing mode desired by the occupant in accordance with the above-mentioned temperatures, the amount of solar radiation, and the like.

[0024] FIG. 3 is a schematic diagram illustrating the configuration of the thermal management system 12. Components already described are designated by the same reference numerals. The refrigeration cycle circuit 30 includes the compressor 34, the outdoor condenser 36, the front and rear evaporators 42F and 42R, and the outdoor condenser 36, as already described. The refrigeration cycle circuit 30 also includes a liquid-cooled condenser 78 that exchanges heat with the heating circuit 32 and a battery cooling heat exchanger 41 that exchanges heat with the battery cooling circuit 40. In the refrigeration cycle circuit 30, adjustable-opening electric expansion valves 84 and 86 are provided upstream of the front evaporator 42F and the battery cooling heat exchanger 41, respectively. An expansion valve 88 and a solenoid valve 90 are provided upstream of the rear evaporator 42R. The electric expansion valves 84 and 86 cannot be completely closed. Even when their openings are at their smallest, a small amount of refrigerant is supplied to the front evaporator 42F and the battery cooling heat exchanger 41. On the other hand, the supply of refrigerant to the rear evaporator 42R can be completely stopped by closing the solenoid valve 90. Furthermore, a heating expansion valve 92 is provided upstream of the outdoor condenser 36. The opening of the heating expansion valve 92 is adjustable and may be an electric expansion valve. When the refrigeration cycle circuit 30 is in heating operation, the refrigerant expands as it passes through the heating expansion valve 92 with its opening reduced, and then vaporizes and absorbs heat in the outdoor condenser 36. Therefore, during heating operation, the outdoor condenser 36 functions as an evaporator. When the refrigeration cycle circuit 30 is in cooling operation, the heating expansion valve 92 is fully open, allowing the refrigerant to simply pass through. The capacity of the refrigeration cycle circuit 30 is adjusted by adjusting the output of the compressor 34 and the opening of each expansion valve 84, 86, 88, and 92.

[0025] The refrigeration cycle circuit 30 has a first bypass flow path 94 arranged in parallel with the front and rear evaporators 42F, 42R and the battery cooling heat exchanger 41. By passing through the first bypass flow path 94, the refrigerant can bypass the front and rear evaporators 42F, 42R and the battery cooling heat exchanger 41. The refrigeration cycle circuit 30 also has a second bypass flow path 96 arranged in parallel with the outdoor condenser 36, and by passing through the second bypass flow path 96, the refrigerant can bypass the outdoor condenser 36.

[0026] The battery cooling circuit 40 includes the battery 18, a battery cooling heat exchanger 41, and a battery cooling circuit pump 98 that circulates coolant between the battery 18 and the battery cooling heat exchanger 41. The battery 18 is cooled by sending coolant cooled in the battery cooling heat exchanger 41 to the battery 18. The battery 18 is provided with a battery temperature sensor 100 that detects the temperature of the battery 18. The level of cooling required for the battery 18 is determined based on the temperature of the battery 18, and the battery cooling circuit 40 is controlled according to the level.

[0027] The heating circuit 32 includes the electric heater 38, the front and rear heater cores 44F, 44R, a liquid-cooled condenser 78, and a heating circuit pump 104 that sends high-temperature liquid. The heating circuit pump 104 circulates circulating liquid through the electric heater 38, the front and rear heater cores 44F, 44R, and the liquid-cooled condenser 78. The liquid-cooled condenser 78 heats the circulating liquid in the heating circuit 32 with high-temperature refrigerant compressed by the compressor 34 of the refrigeration cycle circuit 30 to generate high-temperature liquid. The high-temperature liquid, which is the circulating liquid heated by the electric heater 38 or the liquid-cooled condenser 78, is sent to the front and rear heater cores 44F, 44R. The heating circuit 32 may also include an engine cooling circuit 106, which can utilize the engine 14 as a heat source. The operation of the three-way valve 108 determines whether the high-temperature liquid sent to the front and rear heater cores 44F, 44R is supplied from the engine 14 side or from the electric heater 38 and liquid-cooled condenser 78 side.

[0028] The engine cooling circuit 106 includes the engine 14 and the engine radiator 22, and further includes an engine cooling circuit pump 110 that circulates engine coolant between the engine 14 and the engine radiator 22. The engine cooling circuit 106 also includes a radiator bypass flow path 111 arranged in parallel with the engine radiator 22, allowing the engine coolant to circulate while bypassing the engine radiator 22. When the engine 14 is cold, such as during warm-up, the engine cooling circuit 106 circulates the engine coolant through the radiator bypass flow path 111 without sending it to the engine radiator 22, thereby enabling the temperature of the engine coolant to be increased quickly. As described above, the engine coolant can be shared with the circulating fluid of the heating circuit 32.

[0029] The flow paths of the refrigerant or fluid in the heating circuit 32, including the refrigeration cycle circuit 30, the battery cooling circuit 40, and the engine cooling circuit 106, are changed according to predetermined conditions. The change in the flow path of the refrigerant or fluid is achieved by the operation of the three-way valve 108 and the solenoid valve 90 already described, as well as a plurality of valves (not shown) appropriately provided in each circuit. The opening / closing and opening degree of these valves may be controlled by the control unit 60. The control unit 60 also controls the output of the compressor 34, the discharge flow rate of the battery cooling circuit pump 98, and the discharge flow rate of the heating circuit pump 104 according to requirements.

[0030] The thermal management system 12 operates in several operating modes according to predetermined conditions, which are determined based on, for example, the outside air temperature, the temperature of the airflow blown out from the air conditioning unit 26 based on the passenger demand (requested blowout temperature), and the cooling demand for the battery 18.

[0031] FIG. 4 is a diagram showing an example of conditions that define the operating modes of the thermal management system 12, particularly the operating modes of the air conditioner 26. In the heating region H where the outdoor air temperature is below a predetermined temperature T1 (e.g., 0°C), the thermal management system 12 operates in heating mode, i.e., performs heating operation. In the cooling region C where the outdoor air temperature is higher than the predetermined temperature T1, the required discharge temperature is low, and the difference between the required discharge temperature and the outdoor air temperature is large, the thermal management system 12 operates in cooling mode, i.e., performs cooling operation. In the dehumidifying and heating regions Dp and Ds, which are intermediate between the heating region H and the cooling region C, the thermal management system 12 operates in dehumidifying and heating mode, where the air taken in by the air conditioning unit 28 is first cooled and dehumidified, and then heated to the required discharge temperature, i.e., performs dehumidifying and heating operation. The dehumidifying and heating region is further divided into a parallel dehumidifying and heating region Dp and a series dehumidifying and heating region Ds. The thermal management system 12 performs parallel dehumidifying and heating operation in the parallel dehumidifying and heating region Dp and series dehumidifying and heating operation in the series dehumidifying and heating region Ds. Parallel dehumidifying and heating operation is an operation mode in which heating is stronger than in series dehumidifying and heating operation. Furthermore, if the front air conditioning unit 28F and the rear air conditioning unit 28R can independently set their required discharge temperatures, the required discharge temperature of one of the air conditioning units 28, for example, the front air conditioning unit 28F, which has been predetermined, may be used as a factor for determining the operation mode. Furthermore, the required discharge temperature of the air conditioning unit 28 that is set to a lower temperature may be used as a factor for determining the operation mode. The operation of the thermal management system 12 in each operation mode is described below.

[0032] 5 is a diagram showing the operating state when the temperature of the coolant of the engine 14 is sufficiently high. When the temperature of the engine coolant is high, a portion of the engine coolant circulated by the engine cooling circuit pump 110 is supplied to the heater core 44. Depending on the operation of the occupant, the engine coolant may be supplied to either or both of the front and rear heater cores 44F, 44R.

[0033] 6 is a diagram showing the operating state when the temperature of the engine coolant is low. When the temperature of the engine coolant is low, the electric heater 38 generates high-temperature liquid, which is supplied to the heater core 44 by the heating circuit pump 104. The high-temperature liquid from the electric heater 38 may be supplied to either or both of the front and rear heater cores 44F, 44R by operation of the occupant. In addition, in a vehicle that does not have an engine 14 and runs only on power from the electric motor 16, heating is performed by the electric heater 38 or by operating the heat pump of the refrigeration cycle circuit 30, which will be described below.

[0034] FIG. 7 illustrates the operating state of the refrigeration cycle circuit 30 in heat pump operation for heating. The refrigerant compressed by the compressor 34 and heated to a high temperature is cooled and liquefied in the liquid-cooled condenser 78 by the liquid circulating through the heating circuit 32. At this time, the circulating liquid in the heating circuit 32 is heated by the high-temperature refrigerant and becomes a high-temperature liquid. The refrigerant in the refrigeration cycle circuit 30 liquefied in the liquid-cooled condenser 78 expands as it passes through the heating expansion valve 92 and vaporizes in the outdoor condenser 36, absorbing heat from the outside air. In other words, the outdoor condenser 36 functions as an evaporator. The vaporized refrigerant returns to the compressor 34 through the first bypass flow path 94. The high-temperature liquid heated by the liquid-cooled condenser 78 is supplied to the heater core 44 by the heating circuit pump 104. In this heat pump operation, the passenger compartment 20 is heated by the heat pumped from the outside air. If the heat pump operation is insufficient, the electric heater 38 may be further heated to generate high-temperature liquid.

[0035] FIG. 8 is a diagram showing the operating state of the thermal management system 12 in the cooling region C. In the following description, unless a particular distinction is required, the front evaporator 42F and the rear evaporator 42R will be collectively referred to as the evaporator 42. The refrigerant compressed by the compressor 34 dissipates heat to the outside air in the outdoor condenser 36, where it is cooled and liquefied. The liquefied refrigerant expands as it passes through the electric expansion valve 84 and the expansion valve 88, and then vaporizes and absorbs heat in the front and rear evaporators 42F and 42R, respectively. This cools the passenger compartment 20. Furthermore, when there is no need to cool the rear side of the passenger compartment 20, such as when there are no passengers in the rear seats, the solenoid valve 90 may be closed to prevent refrigerant from being supplied to the rear evaporator 42R.

[0036] FIG. 9 illustrates the operating state of the thermal management system 12 in the parallel dehumidifying and heating zone Dp. The refrigerant compressed by the compressor 34 dissipates heat in the liquid-cooled condenser 78 to the circulating liquid in the heating circuit 32. This generates high-temperature liquid in the heating circuit 32 and supplies it to the heater core 44. As in the heating operation described above, high-temperature liquid may be supplied to either or both of the front and rear heater cores 44F and 44R. In parallel dehumidifying and heating operation, the amount of heat transferred through the refrigeration cycle circuit 30 is less than in heating and cooling operations using a heat pump, reducing the required capacity of the refrigeration cycle circuit 30. Therefore, the output of the compressor 34 is low, and the refrigerant that dissipates heat in the liquid-cooled condenser 78 is not completely liquefied but remains in a two-phase gas-liquid state. A portion of the refrigerant flows toward the outdoor condenser 36, passes through the throttled heating expansion valve 92, and at least a portion of the refrigerant vaporizes and absorbs heat in the outdoor condenser 36. At this time, the outdoor condenser 36 functions as an evaporator. The refrigerant that has passed through the exterior condenser 36 returns to the compressor 34 through the first bypass flow path 94. The remainder of the refrigerant that has passed through the liquid-cooled condenser 78 passes through the second bypass flow path 96 toward the evaporator 42. In the evaporator 42, at least a portion of the liquid-phase refrigerant vaporizes and absorbs heat. After passing through the evaporator 42, the refrigerant returns to the compressor 34. Furthermore, when there is no need to cool the rear side of the passenger compartment 20, such as when there are no passengers in the rear seats, the solenoid valve 90 may be closed to prevent refrigerant from being supplied to the rear evaporator 42R.

[0037] In the air conditioning unit 28, the water vapor is cooled and condensed to dehumidify the air by cooling the air in the evaporator 42. The cooled air is heated by the heater core 44, and the air conditioning unit 28 delivers warm, dry air to the passenger compartment 20.

[0038] FIG. 10 illustrates the operating state of the thermal management system 12 in the series dehumidifying and heating zone Ds. The refrigerant compressed by the compressor 34 dissipates heat to the circulating liquid in the heating circuit 32 in the liquid-cooled condenser 78. This generates high-temperature liquid for the heating circuit 32 and supplies it to the heater core 44. As in the heating operation described above, high-temperature liquid may be supplied to either or both of the front heater core 44F and the rear heater core 44R. The entire refrigerant that passes through the liquid-cooled condenser 78 is sent to the outdoor condenser 36. When the refrigerant dissipates a large amount of heat in the liquid-cooled condenser 78—that is, when heating is performed at a high level—the refrigerant absorbs heat in the outdoor condenser 36, as in the parallel dehumidifying and heating operation. By narrowing the opening of the heating expansion valve 92, a portion of the refrigerant vaporizes and absorbs heat in the outdoor condenser 36. On the other hand, when heating is performed at a low level, the refrigerant dissipates heat in the outdoor condenser 36. In this case, the heating expansion valve 92 is fully open. In the series dehumidifying and heating operation, the amount of heat transferred through the refrigeration cycle circuit 30 is smaller than in the heating and cooling operation using a heat pump, and therefore the capacity required of the refrigeration cycle circuit 30 is smaller. Therefore, the output of the compressor 34 is low, and the refrigerant that has dissipated heat in the liquid-cooled condenser 78 and the exterior condenser 36 is not completely liquefied but remains in a two-phase gas-liquid state. The two-phase gas-liquid refrigerant flows toward the evaporator 42. In the evaporator 42, the liquid refrigerant vaporizes and absorbs heat. After passing through the evaporator 42, the refrigerant returns to the compressor 34. Furthermore, when there is no need to cool the rear side of the passenger compartment 20, such as when there are no passengers in the rear seats, the solenoid valve 90 may be closed to prevent refrigerant from being supplied to the rear evaporator 42R.

[0039] In heating operation, the refrigeration cycle circuit 30 transfers heat from outside the passenger compartment 20 into the passenger compartment 20 to heat the passenger compartment 20, and in cooling operation, it transfers heat from inside the passenger compartment 20 to the outside to cool the passenger compartment. In dehumidifying and heating operation, the refrigeration cycle circuit 30 absorbs heat from the evaporator 42 and radiates heat from the heater core 44 via the heating circuit 32, thereby transferring heat within the passenger compartment 20. The difference between the amount of heat absorbed by the evaporator 42 and the amount of heat radiated by the liquid-cooled condenser 78 is absorbed or radiated by the exterior condenser 36.

[0040] In dehumidifying heating operation, heat transfer is less than in heating and cooling operation, and the output of the compressor 34 is also reduced. Therefore, the refrigerant does not completely liquefy after heat release, but remains in a gas-liquid two-phase state. When a gas-liquid two-phase refrigerant is supplied to multiple targets, the liquid refrigerant may not be distributed evenly.

[0041] In the dehumidifying and heating regions Dp and Ds, when the air conditioning unit 28 operates in a maximum heating mode, the refrigerant is in a two-phase gas-liquid state, resulting in poor efficiency and a failure to achieve a sufficient discharge temperature. In particular, when both the front and rear air conditioning units 28F and 28R are operating (dual mode), the liquid refrigerant is unevenly distributed, resulting in poor efficiency and a failure to achieve the desired performance. When the air conditioning system 26 operates in a maximum heating mode in an inefficient state, the compressor 34 of the refrigeration cycle circuit 30 consumes more power. This reduces the amount of charge stored in the battery 18 and may shorten the vehicle's cruising range. Furthermore, in the dehumidifying and heating regions Dp and Ds, the evaporator 42 cools the air before the heater core 44 heats it, resulting in a correspondingly low discharge air temperature from the air conditioning unit 28. In this case, the desired discharge temperature may not be achieved, or the required power consumption may be increased to achieve the desired discharge temperature.

[0042] In this thermal management system 12, when the front and rear air conditioning units 28F, 28R are operating in the dehumidifying heating zones Dp, Ds, if at least one of the front air conditioning unit 28F and the rear air conditioning unit 28R reaches the maximum heating state, the operation of the refrigeration cycle circuit 30 is stopped and high-temperature liquid is supplied to the front and rear heater cores 44F, 44R by the heating circuit 32. When the temperature of the engine coolant is high, as shown in Fig. 5, coolant from the engine 14 is supplied as high-temperature liquid to the front and rear heater cores 44F, 44R. When the temperature of the engine coolant is low, high-temperature liquid from the electric heater 38 is supplied to the front and rear heater cores 44F, 44R, as shown in Fig. 6.

[0043] 11 is a diagram showing the control flow of the thermal management system 12 when both the front and rear air conditioning units 28F, 28R are operating in the dehumidifying and heating zones Dp, Ds and at least one of them is in the maximum heating state. The control unit 60 controls the thermal management system according to this control flow.

[0044] When the rear air conditioning switch 67 is in the ON state, i.e., the dual mode in which both the front and rear air conditioning units 28F, 28R are operating (S100), and the operating condition is the dehumidifying heating range Dp, Ds (S102), the control unit 60 further determines whether at least one of the front and rear air conditioning units 28F, 28R is in the maximum heating state (S104). If it is determined in step S104 that the maximum heating state is not in effect, the process returns to the start of the control flow. If it is determined in step S104 that the maximum heating state is in effect, the control unit 60 stops operation of the refrigeration cycle circuit 30 and performs heating using the heating circuit 32 as the heat source (S106). If the engine coolant temperature is sufficiently high, the engine 14 is used as the heat source; if the engine coolant temperature is low, the electric heater 38 is used as the heat source. The order of the judgments regarding the three conditions, i.e., the judgment regarding the dual mode (S100), the judgment regarding the dehumidifying heating region (S102), and the judgment regarding the maximum heating state (S104), may be reversed, and when the AND condition of these three conditions is met, the control unit 60 stops operation of the refrigeration cycle circuit 30 and causes the heating circuit 32 to perform heating using only its heat source (S106).

[0045] In another control mode, when the power reduction mode is set in the dehumidifying heating zones Dp, Ds and the front and rear air conditioning units 28F, 28R are operating, if at least one of the front air conditioning unit 28F and the rear air conditioning unit 28R reaches maximum heating mode, the thermal management system 12 stops operation of the refrigeration cycle circuit 30 and supplies high-temperature liquid to the front and rear heater cores 44F, 44R via the heating circuit 32. When the temperature of the engine coolant is high, as shown in FIG. 5, the coolant from the engine 14 is supplied as high-temperature liquid to the front and rear heater cores 44F, 44R. When the temperature of the engine coolant is low, high-temperature liquid from the electric heater 38 is supplied to the front and rear heater cores 44F, 44R, as shown in FIG. 6.

[0046] 12 is a diagram showing the control flow of the thermal management system 12 when the power saving mode is set in the dehumidifying heating zones Dp and Ds, the front and rear air conditioning units 28F and 28R are both operating, and at least one of them is in the maximum heating state. The control unit 60 controls the thermal management system 12 according to this control flow.

[0047] When the rear air conditioning switch 67 is in the ON state, i.e., the dual mode in which both the front and rear air conditioning units 28F, 28R are operating (S100), and the operating condition is the dehumidifying / heating range Dp, Ds (S102), the control unit 60 further determines whether at least one of the front and rear air conditioning units 28F, 28R is in the maximum heating state (S104). If it is determined in step S104 that the maximum heating state is not in effect, the process returns to the start of the control flow. If it is determined in step S104 that the maximum heating state is in effect, the control unit 60 determines whether the power conservation mode is set (S108). If it is determined in step S108 that the power conservation mode is not set, the process returns to the start of the control flow. If it is determined in step S108 that the power conservation mode is in effect, the control unit 60 stops operation of the refrigeration cycle circuit 30 and performs heating using the heat source of the heating circuit 32 (S106). Stopping the refrigeration cycle circuit 30 reduces power consumption by the refrigeration cycle circuit 30. If the temperature of the engine coolant is sufficiently high, the engine 14 is used as the heat source, and if the temperature of the engine coolant is low, the electric heater 38 is used as the heat source. The order of the four conditions, i.e., the determination regarding the dual mode (S100), the determination regarding the dehumidifying heating region (S102), the determination regarding the maximum heating state (S104), and the determination regarding the power saving mode (S108), may be reversed, and when the AND condition of these four conditions is met, the control unit 60 stops operation of the refrigeration cycle circuit 30 and causes the heating circuit 32 to perform heating using only its heat source (S106).

[0048] FIG. 13 is a diagram schematically illustrating the configuration of a thermal management system 112 according to a second embodiment. FIG. 13 illustrates the circuits 130, 132, and 140 of the thermal management system 112, particularly the circuits through which the refrigerant and liquid responsible for heat transfer circulate. Other components, such as the air conditioning unit, are similar to those of the thermal management system 12 described above. The control unit that controls the thermal management system 112 is also similar to the control unit 60 described above. Components similar to those of the thermal management system 12 described above are assigned the same reference numerals, and descriptions thereof will be omitted. The vehicle equipped with the illustrated thermal management system 112 does not include an engine as a prime mover for driving the vehicle, but is driven solely by an electric motor.

[0049] The thermal management system 112 includes front and rear air conditioning units having front and rear evaporators 42F, 42R and front and rear heater cores 44F, 44R. The configurations of these front and rear air conditioning units are similar to the configurations of the front and rear air conditioning units 28F, 28R of the thermal management system 12 described above. In the following description, the air conditioning units of the thermal management system 112 will also be described using the reference numerals 28, 28F, 28R.

[0050] The thermal management system 112 includes a refrigeration cycle circuit 130 that supplies refrigerant to the evaporators 42R, 42F, and a heating circuit 132 that supplies high-temperature liquid to the heater cores 44F, 44R. The refrigeration cycle circuit 130 differs from the above-described refrigeration cycle circuit 30 in that it does not have the outdoor condenser 36, and therefore does not have the first and second bypass flow paths 94, 96 associated with the outdoor condenser 36.

[0051] The heating circuit 132 has a heating circuit radiator 200 that cools the circulating fluid circulating through the heating circuit 132 with outside air. After passing through the electric heater 38, a flow rate regulating three-way valve 202 regulates the flow rate toward the heater core 44 and the flow rate supplied to the heating circuit radiator 200. The circulating fluid in excess of the flow rate required for the heater core 44 is sent to the heating circuit radiator 200. The heating circuit 132 includes a liquid-cooled condenser 78 shared with the refrigeration cycle circuit 130. The circulating fluid in the heating circuit 132 cools and liquefies the high-temperature refrigerant compressed by the compressor 34 of the refrigeration cycle circuit 130 in the liquid-cooled condenser 78. Meanwhile, the circulating fluid itself is heated and sent to the electric heater 38, where it is heated as needed. The high-temperature circulating fluid is then sent to the heater core 44 or the heating circuit radiator 200, where it is cooled.

[0052] The battery cooling circuit 140 circulates battery coolant to cool the battery 18. In an indoor heat exchanger 204 shared with the refrigeration cycle circuit 130, the refrigerant in the refrigeration cycle circuit 130 is liquefied, cooling the battery coolant. This cooled battery coolant is sent to the battery 18. The battery cooling circuit 140 includes an outdoor heat exchanger 206 arranged in parallel with the battery 18. The battery cooling circuit 140 can circulate the battery coolant between the indoor heat exchanger 204 and the outdoor heat exchanger 206. In this case, the battery coolant warmed by outside air in the outdoor heat exchanger 206 warms the refrigerant in the refrigeration cycle circuit 130 in the indoor heat exchanger 204.

[0053] The air conditioner 126 of the thermal management system 112 includes a battery cooling circuit 140 in addition to a refrigeration cycle circuit 130 and a heating circuit 132 .

[0054] FIG. 14 is a diagram showing an example of conditions that define the operating mode of the thermal management system 112, particularly the operating mode of the air conditioner 126. In the heating region H where the outdoor air temperature is below a predetermined temperature T1 (e.g., 0°C), the thermal management system 112 operates in heating mode, i.e., performs heating operation. In the cooling region C where the outdoor air temperature is higher than the predetermined temperature T1, the required discharge temperature is low, and there is a large difference between the required discharge temperature and the outdoor air temperature, the thermal management system 112 operates in cooling mode, i.e., performs cooling operation. In the dehumidifying and heating region D, which is intermediate between the heating region H and the cooling region C, the thermal management system 112 operates in dehumidifying and heating mode, where the air taken in by the air conditioning unit 28 is first cooled and dehumidified, and then heated to the required discharge temperature, i.e., performs dehumidifying and heating operation. In the dehumidifying and heating region, the thermal management system 112 operates in three modes, which will be described later. Furthermore, if the required discharge temperatures can be set independently for the front air conditioning unit 28F and the rear air conditioning unit 28R, the required discharge temperature of one of the air conditioning units 28, for example, the front air conditioning unit 28F, may be used as a factor for determining the operation mode.Alternatively, the required discharge temperature of the air conditioning unit 28 that is set to a lower temperature may be used as a factor for determining the operation mode.

[0055] FIG. 15 shows the operating state of the thermal management system 112 in dehumidifying and heating region D, which is closer to cooling region C, i.e., when cooling is stronger. The refrigeration cycle circuit 130 compresses the refrigerant using the compressor 34, and the compressed refrigerant is cooled by the liquid-cooled condenser 78. In dehumidifying and heating region D, the cooling capacity required by the evaporator 42 is not as high as in cooling region C, so the output of the compressor 34 is low. As a result, some of the refrigerant cooled by the liquid-cooled condenser 78 may not liquefy and may remain in a two-phase gas-liquid state. The refrigerant is then sent to one or both of the front and rear evaporators 42F and 42R. The liquid-phase refrigerant vaporizes in the evaporator 42, absorbs heat, and returns to the compressor 34.

[0056] In the heating circuit 132, the circulating liquid (high-temperature liquid) heated by the refrigerant in the refrigeration cycle circuit 130 in the liquid-cooled condenser 78 is sent to one or both of the front and rear heater cores 44F, 44R, and to the heating circuit radiator 200. The ratio of the flow rate of the high-temperature liquid to the heater core 44 and the heating circuit radiator 200 is adjusted by a flow rate adjustment three-way valve 202. Circulating liquid with a flow rate exceeding the heating requirement of the heater core 44 is sent to the heating circuit radiator 200 and cooled there.

[0057] The heat from the passenger compartment or the outside air absorbed by the evaporator 42 is transferred to the circulating liquid in the heating circuit 132 via the liquid-cooled condenser 78, and a portion of the heat is radiated from the heater core 44 into the passenger compartment, and the remainder is radiated from the heating circuit radiator 200.

[0058] FIG. 16 shows the operating state of the thermal management system 112 in the dehumidifying / heating region D, which is an intermediate condition that is neither close to the cooling region C nor close to the heating region H. The refrigeration cycle circuit 130 compresses the refrigerant using the compressor 34, and the compressed refrigerant is cooled by the liquid-cooled condenser 78. In the dehumidifying / heating region D, the evaporator 42 does not require much cooling capacity, so the output of the compressor 34 is low. As a result, some of the refrigerant cooled by the liquid-cooled condenser 78 may not liquefy and may remain in a two-phase gas-liquid state. The refrigerant is then sent to one or both of the front and rear evaporators 42F and 42R. The refrigerant is also sent to the indoor heat exchanger 204. The refrigerant vaporizes in the evaporator 42 and the indoor heat exchanger 204, absorbs heat, and returns to the compressor 34.

[0059] In the battery cooling circuit 140, the battery coolant is circulated between the indoor heat exchanger 204 and the outdoor heat exchanger 206. In the indoor heat exchanger 204, the battery coolant is cooled by the refrigerant of the refrigeration cycle circuit 130, and then warmed by outside air in the outdoor heat exchanger 206 and returns to the indoor heat exchanger 204.

[0060] In the heating circuit 132, the circulating liquid (high-temperature liquid) heated by the refrigerant in the refrigeration cycle circuit 130 in the liquid-cooled condenser 78 is sent to one or both of the front and rear heater cores 44F, 44R. When the temperature of the circulating liquid in the heating circuit 132 is not sufficiently high by heating with the refrigerant in the refrigeration cycle circuit 130, the circulating liquid heated by the refrigerant is further heated by the electric heater 38 and sent to the heater core 44.

[0061] The heat from the passenger compartment or the outside air absorbed by the evaporator 42 and the heat absorbed by the exterior heat exchanger 206 and transferred to the refrigerant in the interior heat exchanger 204 are transferred to the circulating liquid in the heating circuit 132 via the liquid-cooled condenser 78, and are then radiated from the heater core 44 into the passenger compartment.

[0062] FIG. 17 is a diagram showing the operating state of the thermal management system 112 in a condition closer to the heating region H in the dehumidifying and heating region D, i.e., a condition where heating is strong. The refrigeration cycle circuit 130 operates in the same manner as in the operating state shown in FIG. 15. In this region, the air needs to be sufficiently heated by the heater core 44, and unlike the operating state shown in FIG. 15, the heating circuit 132 further heats the circulating fluid heated by the liquid-cooled condenser 78 using the electric heater 38. Furthermore, the heating circuit 132 does not send circulating fluid to the heating circuit radiator 200. The heat of the passenger compartment or outside air absorbed by the evaporator 42 is transferred to the circulating fluid of the heating circuit 132 via the liquid-cooled condenser 78, and is then radiated from the heater core 44 into the passenger compartment.

[0063] In the dehumidifying and heating region D, the refrigerant in the refrigeration cycle circuit 130 is in a gas-liquid two-phase state after being cooled by the liquid-cooled condenser 78, and the efficiency of the refrigeration cycle is poor. In the dual-mode operation in which both air conditioning units 28F, 28R are operating, the refrigerant may not be properly distributed to the front and rear evaporators 42F, 42R, and the desired performance may not be achieved. Furthermore, in the operating state shown in FIG. 16 , the refrigerant is supplied not only to the front and rear evaporators 42F, 42R but also to the indoor heat exchanger 204. If the refrigerant is in a two-phase gas-liquid state, the refrigerant may not be properly distributed to the two evaporators 42F, 42R, nor to the indoor heat exchanger 204, and heat exchange with the battery coolant in the indoor heat exchanger 204 may be insufficient. In this case, heat transfer from the outside air to the passenger compartment is hindered, reducing the efficiency of the refrigeration cycle circuit 130. If the air conditioning system 126 is operated in maximum heating mode in an inefficient state, the compressor 34 of the refrigeration cycle circuit 130 will consume more power. This may reduce the amount of electricity stored in the battery 18 and shorten the vehicle's cruising range.

[0064] Furthermore, the dehumidifying and heating operation is an operation in which the air in the passenger compartment is first cooled and dehumidified, and then the cooled air is heated. Cooling the air is an unnecessary operation for the purpose of increasing the discharge temperature. Therefore, when the air conditioning device 126 is operated in the maximum heating state, the requested discharge temperature may not be obtained, or the power consumption may increase to achieve the requested discharge temperature.

[0065] Similar to the thermal management system 12 described above, when the front and rear air conditioning units 28F, 28R are operating (dual mode) in the dehumidifying heating area D, if at least one of the front air conditioning unit 28F and the rear air conditioning unit 28R reaches the maximum heating state (MAXHOT), the thermal management system 112 stops operation of the refrigeration cycle circuit 130 and supplies high-temperature liquid to the front and rear heater cores 44F, 44R via the heating circuit 132.

[0066] Specifically, as shown in Fig. 18, the refrigeration cycle circuit 130 is not operated, but the heating circuit 132 is operated to generate high-temperature liquid by the electric heater 38. The high-temperature liquid is supplied to the front and rear heater cores 44F, 44R to perform heating. The control flow is the same as that shown in Fig. 11, and therefore a description thereof will be omitted.

[0067] In another control mode, similar to the thermal management system 12 described above, when the power reduction mode (eco mode) is set in the dehumidifying heating area D and the front and rear air conditioning units 28F, 28R are operating (dual mode), if at least one of the front air conditioning unit 28F and the rear air conditioning unit 28R reaches the maximum heating state (MAXHOT), the thermal management system 112 stops operation of the refrigeration cycle circuit 30 and supplies high-temperature liquid to the front and rear heater cores 44F, 44R via the heating circuit 32.

[0068] Specifically, as shown in Fig. 18, the refrigeration cycle circuit 130 is not operated, but the heating circuit 132 is operated to generate high-temperature liquid by the electric heater 38. The high-temperature liquid is supplied to the front and rear heater cores 44F, 44R to perform heating. The control flow is the same as that shown in Fig. 12, and therefore a description thereof will be omitted.

[0069] In the above-described thermal management systems 12, 112, the air conditioning unit 28 is in the maximum heating state when the air mix door 56 is in the fully open position, but the maximum heating state may also be defined as the position of the air mix door 56 where the ratio of air passing through the heater core 44 to the air discharged from the air conditioning unit 28 is greater than a predetermined value, for example, 90% or greater. [Explanation of symbols]

[0070] 10 Vehicle, 12,112 Thermal management system, 14 Engine, 16 Electric motor, 18 Battery, 20 Passenger compartment, 22 Engine radiator, 26,126 Air conditioning unit, 28 Air conditioning unit, 28F Front air conditioning unit, 28R Rear air conditioning unit, 30,130 Refrigeration cycle circuit, 32,132 Heating circuit, 34 Compressor, 36 Outdoor condenser, 38 Electric heater, 40,140 Battery cooling circuit, 41 Battery cooling heat exchanger, 42 Evaporator, 42F Front evaporator, 42R Rear evaporator, 44 Heater core, 44F Front heater core, 44R Rear heater core, 56 Air mix door, 60 Control unit, 78 Liquid-cooled condenser, 106 Engine cooling circuit, 108 Three-way valve, 202 Flow regulating three-way valve, 204 indoor heat exchanger, 206 outdoor heat exchanger.

Claims

1. a front air conditioning unit that conditions the air in a front space of a vehicle passenger compartment; a rear air conditioning unit that conditions air in a rear space of the vehicle passenger compartment; a refrigeration cycle circuit for supplying refrigerant to the evaporators of the front air conditioning unit and the rear air conditioning unit; a heating circuit that generates a high-temperature liquid by selectively using a heat source and / or a refrigerant in the refrigeration cycle circuit, and supplies the high-temperature liquid to heater cores of the front air conditioning unit and the rear air conditioning unit; A vehicle air conditioning device comprising: In a dehumidifying and heating region determined based on the required blowing temperature, which is a control target for the temperature of the air discharged from the front air conditioning unit and the rear air conditioning unit, and the outside air temperature, when the front air conditioning unit and the rear air conditioning unit are in an operating state and at least one of the front air conditioning unit and the rear air conditioning unit is in a maximum heating state in which the amount of air that has passed through the heater core out of the air discharged from the air conditioning unit is at its maximum, The operation of the refrigeration cycle circuit is stopped, and a heat source heating operation is performed in which the heating circuit generates a high-temperature liquid by utilizing the heat source. Vehicle air conditioning system.

2. a front air conditioning unit that conditions the air in a front space of a vehicle passenger compartment; a rear air conditioning unit that conditions air in a rear space of the vehicle passenger compartment; a refrigeration cycle circuit for supplying refrigerant to the evaporators of the front air conditioning unit and the rear air conditioning unit; a heating circuit that generates a high-temperature liquid by selectively using a heat source and / or a refrigerant in the refrigeration cycle circuit, and supplies the high-temperature liquid to heater cores of the front air conditioning unit and the rear air conditioning unit; A vehicle air conditioning device comprising: In a dehumidifying and heating region determined based on the required blowing temperature, which is a control target for the temperature of the air discharged from the front air conditioning unit and the rear air conditioning unit, and the outside air temperature, when the front air conditioning unit and the rear air conditioning unit are in an operating state, and at least one of the front air conditioning unit and the rear air conditioning unit is in a maximum heating state in which the proportion of air that has passed through the heater core among the air discharged from the air conditioning unit is at its maximum, and when a power reduction mode is selected that reduces the power consumption of a battery that supplies power to an electric motor that drives the vehicle, The operation of the refrigeration cycle circuit is stopped, and a heat source heating operation is performed in which the heating circuit generates the high-temperature liquid by utilizing the heat source. Vehicle air conditioning system.

3. 3. The air conditioning system for a vehicle according to claim 1, wherein the heat source of the heating circuit is one or both of an engine that drives the vehicle and an electric heater.

Images