air conditioning unit

Abstract

An air-conditioning apparatus (8) that carries out air conditioning within a vehicle cabin (80) comprises: a first heat exchange unit (51) which performs heat exchange with the air sent into the vehicle cabin; and a second heat exchange unit (52, 53) that includes an outdoor heat exchanger (16, 55) which is disposed outside the vehicle cabin and which performs heat exchange with outside air. The air-conditioning apparatus also comprises: a refrigeration cycle circuit (10) through which a refrigerant is circulated accompanied with a change of phase thereof and which causes heat to transfer between the first heat exchange unit and the second heat exchange unit through a refrigeration cycle formed through circulation of the refrigerant; and an outdoor air blowing device (56) which is disposed outside the vehicle cabin and which blows outside air to the outdoor heat exchanger. The air-conditioning apparatus further comprises an air blowing control unit (70, 76). When the outside air temperature (TAM) is at a temperature at which the outdoor air blowing device in a non-operating state has a possibility of freezing, the air blowing control unit operates the outdoor air blowing device regardless of whether or not the refrigeration cycle circuit is in a cycle action.

Description

Cross - reference to related applications

[0001] This application is based on Japanese Patent Application No. 2023 - 31101 filed on March 1, 2023, the contents of which are incorporated herein by reference.

Technical Field

[0002] The present disclosure relates to an air - conditioning device for air - conditioning the interior of a vehicle.

Background Art

[0003] As this type of air - conditioning device, for example, a vehicle air - conditioning device described in Patent Document 1 has been conventionally known. The vehicle air - conditioning device described in Patent Document 1 can perform heating and cooling of the vehicle interior using a refrigeration cycle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] Normally, an air - conditioning device such as the vehicle air - conditioning device of Patent Document 1 includes an outdoor heat exchanger that is arranged outside the vehicle and performs heat exchange with the outside air. And although not explicitly described in Patent Document 1, generally, the air - conditioning device also includes an outdoor air - blowing device that blows air to the outdoor heat exchanger. Since this outdoor air - blowing device is arranged outside the vehicle together with the outdoor heat exchanger, for example, the temperature around the outdoor air - blowing device may be below freezing. In that case, depending on the situation, the outdoor air - blowing device may freeze. When the outdoor air - blowing device is operated in a frozen state, there is a risk of failure of the outdoor air - blowing device.

[0006] For example, in an air conditioning system that switches between cooling and heating using a refrigeration cycle, such as the vehicle air conditioning system described in Patent Document 1, it is assumed that the outdoor fan will be operated even at sub-zero temperatures in order to allow the outdoor heat exchanger to absorb heat from the outside air during heating. The inventors found the above after detailed examination.

[0007] In view of the above points, this disclosure aims to provide an air conditioning system capable of preventing malfunctions caused by freezing of the outdoor ventilation system.

[0008] To achieve the above objective, an air conditioning system according to one aspect of this disclosure is: An air conditioning system that provides air conditioning for the interior of a vehicle, A first heat exchange unit that performs heat exchange with the air sent into the vehicle interior, A second heat exchange unit, which includes an outdoor heat exchanger located outside the vehicle and performing heat exchange with the outside air, A refrigeration cycle circuit in which a refrigerant circulates with a phase change, and heat is transferred between a first heat exchange section and a second heat exchange section by a refrigeration cycle caused by the circulation of the refrigerant, An outdoor ventilation system located outside the vehicle cabin that directs outside air to the outdoor heat exchanger, The system includes a fan control unit that activates the outdoor fan regardless of whether the refrigeration cycle circuit is in cycle operation, if the outside air temperature reaches a temperature at which the non-operating outdoor fan could freeze.

[0009] In this way, when the outside air temperature reaches a level where the outdoor fan unit, which is not currently operating, could freeze, the outdoor fan unit will operate even if it does not need to circulate outside air to the outdoor heat exchanger. This prevents the outdoor fan unit from freezing, thus preventing malfunctions caused by freezing.

[0010] In addition, each element in the application documents may be given a reference numeral in parentheses. In this case, the reference numeral merely indicates one example of the correspondence between the element and the specific configuration described in the embodiments described later. Therefore, this disclosure is not limited in any way by the inclusion of such reference numerals. [Brief explanation of the drawing]

[0011] [Figure 1] This is an overall configuration diagram showing the circuit configuration of the refrigeration cycle circuit, the circuit configuration of the heat transfer medium circuit, and the schematic configuration of the indoor air conditioning unit in the air conditioning system of the first embodiment. [Figure 2] In the first embodiment, this figure shows the refrigerant flow in the refrigeration cycle circuit during cooling operation of an air conditioning system, and corresponds to Figure 1. [Figure 3] In the first embodiment, this figure shows the refrigerant flow in the refrigeration cycle circuit during heating operation of the air conditioning system, and corresponds to Figure 1. [Figure 4] This diagram schematically shows the arrangement of the outdoor heat exchanger and the outdoor ventilation device in the first embodiment. [Figure 5] This is a block diagram showing the input / output system of a control device in the first embodiment of the air conditioning system. [Figure 6] This is a flowchart illustrating the control process performed by the control device in the first embodiment. [Figure 7] This is an overall configuration diagram showing the circuit configuration of the refrigeration cycle circuit, the circuit configuration of each heat transfer medium circuit, and the schematic configuration of the indoor air conditioning unit in the air conditioning system of the second embodiment, and corresponds to Figure 1. [Figure 8] In the second embodiment, this figure shows the refrigerant flow in the refrigeration cycle circuit when the air conditioning system is operating in cooling mode and battery cooling mode simultaneously, and corresponds to Figure 2. [Figure 9] This is an overall configuration diagram showing the circuit configuration of the refrigeration cycle circuit, the circuit configuration of each heat transfer medium circuit, and the schematic configuration of the indoor air conditioning unit in the air conditioning system of the third embodiment, and corresponds to Figure 1. [Figure 10] This is a power circuit diagram schematically showing the electrical connection relationship between the outdoor air blower and the power source in the fourth embodiment.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, each embodiment will be described with reference to the drawings. In the following embodiments, parts that are identical or equivalent to each other are denoted by the same reference numerals in the drawings.

[0013] (First Embodiment) FIG. 1 is an overall configuration diagram schematically showing an air conditioner 8 for a vehicle in this embodiment. The air conditioner 8 includes a refrigeration cycle circuit 10 in which a refrigerant circulates with a phase change, and performs air conditioning in the vehicle interior 80. For this purpose, the refrigeration cycle circuit 10 can be selectively switched between a cooling mode in which the blower air sent into the vehicle interior 80, which is the air conditioning target space, is cooled to cool the vehicle interior 80, and a heating mode in which the blower air is heated to heat the vehicle interior 80. That is, the refrigeration cycle circuit 10 plays a role of heating or cooling the blower air sent into the vehicle interior 80 in the air conditioner 8. The cooling mode of the refrigeration cycle circuit 10 may be referred to as the first mode, and the heating mode of the refrigeration cycle circuit 10 may be referred to as the second mode.

[0014] The air conditioner 8 shown in FIG. 1 is mounted on, for example, a hybrid vehicle that obtains driving force for vehicle travel from an internal combustion engine (that is, an engine) and a driving electric motor. The air conditioner 8 includes a refrigeration cycle circuit 10, a heat medium circuit 40, an outdoor air blower 56, an indoor air conditioning unit 60, and a control device 70 (see FIG. 5), etc.

[0015] The refrigeration cycle circuit 10 of the air conditioner 8 is a refrigerant circulation circuit in which a refrigerant circulates with a phase change. The refrigeration cycle circuit 10 is configured to be switchable between a refrigerant circuit in the cooling mode in which the refrigerant circulates as shown by the arrow FLc in FIG. 2 and a refrigerant circuit in the heating mode in which the refrigerant circulates as shown by the arrow FLh in FIG. 3. In FIGS. 2 and 3, flow paths through which the refrigerant does not flow are indicated by broken lines.

[0016] In the refrigeration cycle circuit 10, since the refrigerant circulates with a phase change, a refrigeration cycle (specifically, a vapor compression subcritical refrigeration cycle) by the circulation of the refrigerant is executed. As the refrigerant of the refrigeration cycle circuit 10, for example, an HFC refrigerant such as R134a or an HFO refrigerant such as R1234yf can be adopted.

[0017] As shown in FIGS. 1 to 3, the refrigeration cycle circuit 10 has a compressor 11, a water-cooled condenser 12, a heating expansion valve 14 as a first expansion valve, an outdoor heat exchanger 16, an on-off valve 18, and a cooling expansion valve 20 as a second expansion valve. Further, the refrigeration cycle circuit 10 has an indoor evaporator 22, an accumulator 24, a refrigerant pipe through which the refrigerant flows, and various sensors (not shown).

[0018] The compressor 11 has a suction port 111 and a discharge port 112, and is disposed in the engine room. The engine room is a part outside the passenger compartment 80.

[0019] The compressor 11 sucks the refrigerant from the suction port 111 in the refrigeration cycle circuit 10, compresses it, and discharges the compressed and superheated refrigerant from the discharge port 112. The refrigerant inlet 121 of the water-cooled condenser 12 is connected to the discharge port 112 of the compressor 11. The compressor 11 of the present embodiment is, for example, an electric compressor. As the compression mechanism of the compressor 11, specifically, various compression mechanisms such as a scroll type compression mechanism and a vane type compression mechanism can be adopted.

[0020] The electric motor of the compressor 11 is controlled in its operation (specifically, the rotational speed) by a control signal output from the control device 70. As the electric motor, either an AC motor or a DC motor may be adopted.

[0021] The water-cooled condenser 12 has a refrigerant inlet 121 through which the refrigerant from the refrigeration cycle circuit 10 flows in, a refrigerant outlet 122 through which the refrigerant flows out, a heat medium inlet 123 through which the heat medium circulating in the heat medium circuit 40 flows in, and a heat medium outlet 124 through which the heat medium flows out. The water-cooled condenser 12 is a heat exchanger that exchanges heat between the refrigerant from the refrigeration cycle circuit 10 and the heat medium from the heat medium circuit 40, and through the heat exchange between the refrigerant and the heat medium it condenses the refrigerant and heats the heat medium.

[0022] The refrigerant that has been heated and condensed in the water-cooled condenser 12 flows out from the refrigerant outlet 122, and at the same time, the heat transfer medium heated in the water-cooled condenser 12 flows out from the heat transfer medium outlet 124. The refrigerant outlet 122 of the water-cooled condenser 12 is connected to the refrigerant inlet 141 of the heating expansion valve 14. Since the water-cooled condenser 12 is installed across the refrigeration cycle circuit 10 and the heat transfer medium circuit 40, it constitutes a part of the refrigeration cycle circuit 10 and a part of the heat transfer medium circuit 40.

[0023] The heating expansion valve 14 has a refrigerant inlet 141 through which the refrigerant from the refrigeration cycle circuit 10 flows in, and a refrigerant outlet 142 through which the refrigerant flows out. The heating expansion valve 14 is a pressure reducing device that reduces the pressure of the refrigerant. That is, the heating expansion valve 14 reduces the pressure of the refrigerant that flows into the heating expansion valve 14 from the refrigerant inlet 141, and then discharges the reduced-pressure refrigerant to the outside from the refrigerant outlet 142.

[0024] For example, the heating expansion valve 14 is an electric expansion valve and has a valve body and an electric actuator. The electric actuator of the heating expansion valve 14 is configured to include, for example, a stepping motor, and changes the throttle opening of the heating expansion valve 14 by displacing the valve body. Since the electric actuator of the heating expansion valve 14 is controlled by a control signal from the control device 70 (see Figure 5), the throttle opening of the heating expansion valve 14 is increased or decreased in accordance with the control signal from the control device 70.

[0025] Furthermore, when the refrigeration cycle circuit 10 is in cooling mode, the heating expansion valve 14 is set to a fully open state, allowing refrigerant to flow from the refrigerant inlet 141 to the refrigerant outlet 142 without restricting the flow. In other words, the heating expansion valve 14 is configured to be in a fully open state, as well as a state where it can restrict the flow of refrigerant from the refrigerant inlet 141 to the refrigerant outlet 142 to reduce pressure.

[0026] The outdoor heat exchanger 16 is located outside the passenger compartment 80, as shown in Figure 4, for example, on the lower side of the vehicle 78 relative to the passenger compartment 80. The outdoor heat exchanger 16 is installed in a horizontal or nearly horizontal position. That is, the outdoor heat exchanger 16 is installed so that the air passing through it flows from bottom to top, as indicated by arrows A1 and A2. Note that arrow Da in Figure 4 represents the vertical direction of the vehicle 78, and arrow Db represents the longitudinal direction of the vehicle 78.

[0027] As shown in Figure 1, the outdoor heat exchanger 16 has a refrigerant inlet 161 through which the refrigerant from the refrigeration cycle circuit 10 flows in, and a refrigerant outlet 162 through which the refrigerant flows out. The refrigerant outlet 142 of the heating expansion valve 14 is connected to the refrigerant inlet 161 of the outdoor heat exchanger 16, and refrigerant flows in from the heating expansion valve 14. The outdoor heat exchanger 16 is a heat exchanger that performs heat exchange with the outside air, which is the air outside the vehicle compartment 80.

[0028] In other words, the outdoor heat exchanger 16 exchanges heat between the outside air passing through the outdoor heat exchanger 16 and the refrigerant circulating within the outdoor heat exchanger 16. More specifically, when the refrigeration cycle circuit 10 is in cooling mode, the outdoor heat exchanger 16 functions as an outdoor condenser, releasing heat to the outside air through heat exchange between the outside air and the refrigerant, while also condensing the refrigerant. On the other hand, when the refrigeration cycle circuit 10 is in heating mode, the outdoor heat exchanger 16 functions as an outdoor evaporator, absorbing heat from the outside air through heat exchange between the outside air and the refrigerant, while also evaporating the refrigerant.

[0029] The shut-off valve 18 has a refrigerant inlet 181 through which the refrigerant from the refrigeration cycle circuit 10 flows in, and a refrigerant outlet 182 through which the refrigerant flows out. The refrigerant inlet 181 of the shut-off valve 18 is connected to the refrigerant outlet 162 of the outdoor heat exchanger 16, and the refrigerant outlet 182 of the shut-off valve 18 is connected to the refrigerant inlet 241 of the accumulator 24.

[0030] The on-off valve 18 is a solenoid valve, and its operation is controlled by a control signal from the control device 70. In other words, the on-off valve 18 opens and closes the refrigerant flow passage between the refrigerant inlet 181 and the refrigerant outlet 182 in response to the control signal. To put it another way, the on-off valve 18 opens and closes the refrigerant flow passage from the refrigerant outlet 162 of the outdoor heat exchanger 16 to the refrigerant inlet 241 of the accumulator 24.

[0031] For example, when the on-off valve 18 is in the open state, the refrigerant flow passage between the refrigerant inlet 181 and the refrigerant outlet 182 is opened, allowing refrigerant to flow from the refrigerant inlet 181 to the refrigerant outlet 182. Conversely, when the on-off valve 18 is in the closed state (in other words, the blocked state), the refrigerant flow passage between the refrigerant inlet 181 and the refrigerant outlet 182 is blocked, making it impossible for refrigerant to flow from the refrigerant inlet 181 to the refrigerant outlet 182.

[0032] The cooling expansion valve 20 has a refrigerant inlet 201 through which the refrigerant from the refrigeration cycle circuit 10 flows in, and a refrigerant outlet 202 through which the refrigerant flows out. The cooling expansion valve 20 is a pressure reducing device that reduces the pressure of the refrigerant. That is, the cooling expansion valve 20 reduces the pressure of the refrigerant that flows into the cooling expansion valve 20 from the refrigerant inlet 201, and the reduced pressure of the refrigerant flows out to the outside from the refrigerant outlet 202. The refrigerant inlet 201 of the cooling expansion valve 20 is connected to the refrigerant outlet 162 of the outdoor heat exchanger 16, and the refrigerant outlet 202 of the cooling expansion valve 20 is connected to the refrigerant inlet 221 of the indoor evaporator 22.

[0033] For example, the cooling expansion valve 20 is an electric expansion valve whose throttle opening is increased or decreased in accordance with a control signal from the control device 70, similar to the heating expansion valve 14. However, the cooling expansion valve 20 is configured to allow its throttle opening to be set to zero, that is, to allow the cooling expansion valve 20 to be completely closed.

[0034] Therefore, the cooling expansion valve 20 can not only be in a pressure adjustment state, which restricts the flow of refrigerant from the refrigerant inlet 201 to the refrigerant outlet 202 to reduce pressure, but also in a fully closed state. When the cooling expansion valve 20 is in the fully closed state, the flow of refrigerant from the outdoor heat exchanger 16 to the indoor evaporator 22 is blocked. When the cooling expansion valve 20 is open, i.e., in the pressure adjustment state, the refrigerant reduced in pressure by the cooling expansion valve 20 flows out from the refrigerant outlet 202 of the cooling expansion valve 20 and flows to the refrigerant inlet 221 of the indoor evaporator 22.

[0035] The indoor evaporator 22 has a refrigerant inlet 221 into which the refrigerant flows, and a refrigerant outlet 222 that discharges the refrigerant after heat exchange within the indoor evaporator 22. The refrigerant outlet 222 of the indoor evaporator 22 is connected to the refrigerant inlet 241 of the accumulator 24.

[0036] The indoor evaporator 22 is located within the casing 61 of the indoor air conditioning unit 60, upstream of the indoor heater 42 from the airflow. The indoor evaporator 22 functions as a cooling heat exchanger that cools the airflow when the refrigeration cycle circuit 10 is in cooling mode. Specifically, the indoor evaporator 22 exchanges heat between the refrigerant flowing out from the cooling expansion valve 20 and the airflow inside the casing 61, thereby evaporating the refrigerant and cooling the airflow. Although the indoor evaporator 22 constitutes part of the refrigeration cycle circuit 10, it is also part of the indoor air conditioning unit 60 because it is located within the casing 61 of the indoor air conditioning unit 60.

[0037] The indoor air conditioning unit 60 is equipped with an indoor blower 65 upstream of the indoor evaporator 22. The indoor blower 65 sends the blown air to the indoor evaporator 22, and the blown air that has passed through the indoor evaporator 22 flows into the vehicle compartment 80 as shown by arrow FN.

[0038] The accumulator 24 has a refrigerant inlet 241 through which the refrigerant from the refrigeration cycle circuit 10 flows in, and a refrigerant outlet 242 through which the refrigerant flows out. The refrigerant outlet 242 of the accumulator 24 is connected to the suction port 111 of the compressor 11.

[0039] The accumulator 24 separates the gaseous and liquid phases of the refrigerant flowing in from the refrigerant inlet 241, and stores the liquid phase refrigerant. The accumulator 24 then discharges mainly the gaseous phase refrigerant from the refrigerant outlet 242 to the suction port 111 of the compressor 11.

[0040] The outdoor ventilation device 56 is an electric fan that blows outside air to the outdoor heat exchanger 16. In this embodiment, the outdoor ventilation device 56 is, for example, an axial flow fan. The outdoor ventilation device 56 operates according to electrical signals output from the control device 70. That is, the control device 70 functions as a ventilation control unit that controls the operation of the outdoor ventilation device 56.

[0041] For example, the output of the outdoor fan 56 (more specifically, the airflow output of the outdoor fan 56 to blow outside air) is increased or decreased according to a control signal from the control device 70, and the control device 70 can continuously control the output of the outdoor fan 56 from zero to maximum output. When the output of the outdoor fan 56 is zero, the outdoor fan 56 stops rotating, and when the output of the outdoor fan 56 is at maximum output, the rotation speed of the outdoor fan 56 becomes maximum. The outdoor fan 56 is basically controlled according to the operating status of the refrigeration cycle circuit 10.

[0042] Furthermore, as shown in Figure 4, the outdoor ventilation unit 56 is located outside the passenger compartment 80, for example, on the lower side of the vehicle 78 relative to the passenger compartment 80 and on the upper side relative to the outdoor heat exchanger 16. The outdoor ventilation unit 56 is installed in such a position that the rotation axis of its impeller is oriented vertically or approximately vertically. In other words, the outdoor ventilation unit 56 is installed to blow air from bottom to top, as indicated by arrows A1 and A2.

[0043] As shown in Figure 1, the heat transfer medium circuit 40 is a fluid circuit in which a liquid heat transfer medium circulates. In addition to the water-cooled condenser 12 described above, the heat transfer medium circuit 40 includes a pump 41, an indoor heater 42, a heat transfer medium heater 43, and piping connecting them.

[0044] Pump 41 has an inlet 411 and a discharge port 412. The inlet 411 of pump 41 is connected to the heat transfer medium outlet 422 of the indoor heater 42, and the discharge port 412 of pump 41 is connected to the heat transfer medium inlet 123 of the water-cooled condenser 12. Pump 41 is an electric pump that pumps the heat transfer medium and operates according to a control signal from the control device 70.

[0045] Pump 41 draws the heat transfer medium into the pump 41 through the inlet 411 and discharges the drawn-in heat transfer medium from the discharge port 412 to the heat transfer medium inlet 123 of the water-cooled condenser 12. As a result, the heat transfer medium circulates in the heat transfer medium circuit 40, enabling heat exchange between the water-cooled condenser 12 and the indoor heater 42.

[0046] The indoor heater 42 is located inside the casing 61 of the indoor air conditioning unit 60. Although the indoor heater 42 constitutes part of the heat transfer medium circuit 40, it also constitutes part of the indoor air conditioning unit 60 because it is located inside the casing 61 of the indoor air conditioning unit 60.

[0047] The indoor heater 42 has a heat medium inlet 421 through which the heat medium of the heat medium circuit 40 flows in, and a heat medium outlet 422 through which the heat medium flows out. The heat medium inlet 421 of the indoor heater 42 is connected to the heat medium outlet 124 of the water-cooled condenser 12 via a heat medium heater 43.

[0048] The indoor heater 42 is a heat exchanger that exchanges heat between a heat transfer medium and air. Specifically, the indoor heater 42 exchanges heat between the heat transfer medium that flows into the indoor heater 42 from the heat transfer medium inlet 421 and the blown air that flows through the casing 61 and passes through the indoor heater 42, thereby heating the blown air. The heat transfer medium after the heat exchange flows out from the heat transfer medium outlet 422 of the indoor heater 42 and is drawn into the suction port 411 of the pump 41.

[0049] The heat transfer medium heater 43 heats the heat transfer medium that flows from the heat transfer medium outlet 124 of the water-cooled condenser 12 to the heat transfer medium inlet 421 of the indoor heater 42. For example, the heat transfer medium heater 43 is an electric heater that heats the heat transfer medium when power is supplied to it, and the magnitude of the current flowing through the heat transfer medium heater 43 is increased or decreased by a control signal from the control device 70. The control device 70 can adjust the amount of heat supplied to the heat transfer medium by adjusting the current flowing through the heat transfer medium heater 43.

[0050] In the heat transfer medium circuit 40 configured in this way, the heat transfer medium circulates when the pump 41 is operated. The heat transfer medium discharged from the discharge port 412 of the pump 41 flows in the order of water-cooled condenser 12, heat transfer medium heater 43, and indoor heater 42, and is then drawn from the indoor heater 42 to the suction port 411 of the pump 41.

[0051] In addition to the casing 61, indoor evaporator 22, and indoor heater 42 described above, the indoor air conditioning unit 60 includes an air passage switching door 63 and an indoor blower 65.

[0052] The casing 61 is the outer shell of the indoor air conditioning unit 60. Inside the casing 61, a hot air passage 61a and a cold air passage 61b are formed in parallel to each other, and the indoor heater 42 is located in the hot air passage 61a. In other words, the hot air passage 61a is an air passage that directs the air that has passed through the indoor evaporator 22 to the indoor heater 42, and the cold air passage 61b is an air passage that directs the air that has passed through the indoor heater 42, bypassing it.

[0053] The airflow passage switching door 63 is operated by a control signal output from the control device 70. This airflow passage switching door 63 rotates as shown by arrow B1 between a first door position that closes the hot air passage 61a while opening the cold air passage 61b, and a second door position that opens the hot air passage 61a while closing the cold air passage 61b.

[0054] For example, the airflow passage switching door 63 is positioned at the first door position when the air conditioning unit 8 is in cooling operation, and at the second door position when the air conditioning unit 8 is in heating operation. Then, when the air conditioning unit 8 is in dehumidification operation, the airflow passage switching door 63 is positioned at the second door position, or at a door position between the first door position and the second door position.

[0055] In the casing 61, multiple openings (not shown) are provided downstream of the airflow of the warm air passage 61a and the cold air passage 61b, for blowing the air that has passed through the warm air passage 61a or the cold air passage 61b (i.e., conditioned air) into the passenger compartment 80. Specifically, these openings include face openings that blow conditioned air towards the upper bodies of occupants in the passenger compartment 80, foot openings that blow conditioned air towards the feet of occupants, and defroster openings that blow conditioned air towards the inner surface of the vehicle's front window glass. Each opening is provided with an opening / closing door for opening and closing the opening.

[0056] The indoor blower 65 is an electric blower controlled by a control signal output from the control device 70. The indoor blower 65 is located upstream of the indoor evaporator 22 in the indoor air conditioning unit 60. When the indoor blower 65 operates, a flow of air is generated within the casing 61 toward the passenger compartment 80.

[0057] As shown in Figure 5, the control device 70 is an electronic control device composed of a semiconductor memory as a non-transitional physical recording medium, a computer including a processor, and its peripheral circuits. The control device 70 executes a computer program stored in its semiconductor memory. When this computer program is executed, methods corresponding to the computer program are performed. That is, the control device 70 performs various control processes according to the computer program.

[0058] The output side of the control device 70 is connected to the compressor 11, heating expansion valve 14, on-off valve 18, cooling expansion valve 20, pump 41, heat transfer medium heater 43, outdoor blower 56, air passage switching door 63, and indoor blower 65, among others.

[0059] Multiple sensors included in the air conditioning unit 8 are connected to the input side of the control device 70. For example, an indoor air temperature sensor 71 for detecting the temperature of the air inside the passenger compartment 80, an outdoor air temperature sensor 72 for detecting the temperature of the air outside the passenger compartment 80, i.e., the outside air temperature, and a solar radiation sensor 73 are connected to the input side of the control device 70. In addition, a refrigerant pressure sensor 74 for detecting the refrigerant pressure at the discharge port 112 of the compressor 11 is also connected to the input side of the control device 70.

[0060] In the air conditioning system 8 configured as described above, cooling, heating, and dehumidification operations are performed. For example, when the air conditioning system 8 is in cooling operation, as shown in Figure 2, the control device 70 opens the heating expansion valve 14 to the fully open state, shuts off the on / off valve 18, sets the cooling expansion valve 20 to a pressure adjustment state, and activates the compressor 11.

[0061] These controls put the refrigeration cycle circuit 10 into cooling mode, and the refrigerant circulates in the refrigeration cycle circuit 10 as shown by the arrow FLc. That is, the refrigerant discharged from the outlet 112 of the compressor 11 flows in the following order: water-cooled condenser 12, heating expansion valve 14, outdoor heat exchanger 16, cooling expansion valve 20, indoor evaporator 22, and accumulator 24, and is then drawn from the accumulator 24 to the inlet 111 of the compressor 11.

[0062] Furthermore, when the air conditioning unit 8 is in cooling operation, the pump 41 of the heat transfer medium circuit 40 is stopped. As a result, the heat transfer medium does not circulate in the heat transfer medium circuit 40, and therefore no heat exchange occurs between the heat transfer medium and the refrigerant in the water-cooled condenser 12.

[0063] Furthermore, when the air conditioning unit 8 is in cooling operation, the airflow passage switching door 63 is positioned at the first door position and the indoor fan 65 is activated.

[0064] During the cooling operation of the air conditioning system 8, the operation of each component causes the indoor evaporator 22 to cool the air supplied to the passenger compartment 80, while the outdoor heat exchanger 16 releases heat to the outside air. In this way, cool air is supplied to the passenger compartment 80, and the passenger compartment 80 is cooled.

[0065] When the air conditioning unit 8 is in dehumidification mode, the control of each control device in the refrigeration cycle circuit 10 is the same as when the air conditioning unit 8 is in cooling mode. That is, the refrigeration cycle circuit 10 is in cooling mode, and the refrigerant circulates in the refrigeration cycle circuit 10 as shown by the arrow FLc.

[0066] However, when the air conditioning unit 8 is in dehumidification operation, the pump 41 of the heat transfer medium circuit 40 is activated. Then, in the indoor air conditioning unit 60, the air passage switching door 63 is positioned at the second door position, or at a door position between the first door position and the second door position, and the indoor blower 65 is activated. As a result, the air blown by the indoor blower 65 is cooled in the indoor evaporator 22 and then heated in the indoor heater 42, so that dehumidified air is supplied into the vehicle compartment 80, and dehumidification is carried out inside the vehicle compartment 80.

[0067] When the air conditioning unit 8 is in heating operation, as shown in Figure 3, the control device 70 will, The heating expansion valve 14 is set to a pressure-regulating state, the on / off valve 18 is set to an open state, the cooling expansion valve 20 is set to a fully closed state, and the compressor 11 is activated.

[0068] These controls put the refrigeration cycle circuit 10 into heating mode, and the refrigerant circulates in the refrigeration cycle circuit 10 as indicated by the arrow FLh. That is, the refrigerant discharged from the outlet 112 of the compressor 11 flows in the following order: water-cooled condenser 12, heating expansion valve 14, outdoor heat exchanger 16, on-off valve 18, and accumulator 24, and is then drawn from the accumulator 24 to the inlet 111 of the compressor 11. At this time, no refrigerant flows through the indoor evaporator 22, so the air blown into the casing 61 passes through the indoor evaporator 22 without being cooled by it.

[0069] Furthermore, when the air conditioning unit 8 is operating in heating mode, the pump 41 of the heat transfer medium circuit 40 is activated. As a result, the heat transfer medium circulates in the heat transfer medium circuit 40, allowing the refrigerant in the water-cooled condenser 12 to exchange heat with the air blown through the indoor heater 42 via the heat transfer medium in the heat transfer medium circuit 40.

[0070] Furthermore, when the air conditioning unit 8 is operating in heating mode, the airflow passage switching door 63 is positioned at the second door position and the indoor fan 65 is activated.

[0071] During heating operation of the air conditioning system 8, the operation of each component causes the air supplied to the passenger compartment 80 to pass through the indoor evaporator 22 without being cooled by the indoor evaporator 22, and is heated by the indoor heater 42. The outdoor heat exchanger 16 then absorbs heat from the outside air. In this way, warm air is supplied to the passenger compartment 80, and heating is performed inside the passenger compartment 80.

[0072] As can be seen from the cooling, heating, and dehumidifying operations of the air conditioning unit 8 described above, the heat transfer medium circuit 40 and the indoor evaporator 22 of the air conditioning unit 8 constitute a first heat exchange unit 51 that exchanges heat between the air supplied to the passenger compartment 80 and the refrigerant of the refrigeration cycle circuit 10. In other words, the first heat exchange unit 51, which is composed of the heat transfer medium circuit 40 and the indoor evaporator 22, is a heat exchange unit that exchanges heat with the air supplied.

[0073] In contrast, the outdoor heat exchanger 16 of the air conditioning unit 8 constitutes a second heat exchange section 52 that performs heat exchange between the outside air and the refrigerant of the refrigeration cycle circuit 10. That is, the second heat exchange section 52 is a heat exchange section that performs heat exchange with the outside air.

[0074] Furthermore, during cooling, heating, or dehumidifying operation of the air conditioning unit 8, the refrigeration cycle circuit 10 transfers heat between the first heat exchange unit 51 and the second heat exchange unit 52 through a refrigeration cycle involving the circulation of refrigerant.

[0075] For example, when the air conditioner 8 is in cooling mode, the refrigeration cycle circuit 10 enters cooling mode and performs a first operation to transfer heat from the first heat exchange unit 51 to the second heat exchange unit 52. In contrast, when the air conditioner 8 is in heating mode, the refrigeration cycle circuit 10 enters heating mode and performs a second operation to transfer heat from the second heat exchange unit 52 to the first heat exchange unit 51. In other words, the refrigeration cycle circuit 10 is configured to switch between its first and second operations.

[0076] Next, the control of the outdoor ventilation system 56 by the control device 70 will be described. For example, when the ignition switch of the vehicle 78 is turned on, the control device 70 starts the control process shown in Figure 6.

[0077] As shown in Figure 6, in step S01, the control device 70 first obtains the ambient temperature, i.e., the ambient temperature TAM, detected by the ambient temperature sensor 72 from the ambient temperature sensor 72. The control device 70 then determines whether or not the ambient temperature TAM is below a predetermined ambient temperature threshold T1.

[0078] For example, the maximum temperature at which the outdoor fan 56 may freeze when it is stopped and not operating has been experimentally determined in advance. The ambient temperature threshold T1 is set to the maximum temperature at which the outdoor fan 56 may freeze when it is stopped. For example, in this embodiment, the ambient temperature threshold T1 is set to a certain temperature between 0 and 5°C. More specifically, freezing of the outdoor fan 56 means that the rotating parts of the outdoor fan 56, such as the impeller or motor, become unable to rotate due to the freezing of moisture adhering to the outdoor fan 56.

[0079] If it is determined in step S01 that the outside temperature TAM is less than or equal to the outside temperature threshold T1, the process proceeds to step S03. On the other hand, if it is determined that the outside temperature TAM is higher than the outside temperature threshold T1, the process proceeds to step S02.

[0080] In step S02, the control device 70 sets the output instruction value Px that determines the output of the outdoor fan 56 to a load-responsive output value Pf corresponding to the cycle load of the refrigeration cycle circuit 10. This output instruction value Px is output as a control signal from the control device 70 to the outdoor fan 56, and the outdoor fan 56 is driven according to that output instruction value Px. Therefore, determining the output instruction value Px is equivalent to determining the output or rotational speed of the outdoor fan 56.

[0081] The output instruction value Px, the load-responding output value Pf, and the output lower limit value P0 described later may be values ​​that represent the output of the outdoor fan 56 itself, or they may be index values ​​corresponding to the output of the outdoor fan 56 (for example, a ratio to the maximum output).

[0082] Furthermore, the larger the output indicator value Px and the load-response output value Pf, the greater the output of the outdoor fan 56. The maximum values ​​of the output indicator value Px and the load-response output value Pf represent the maximum output of the outdoor fan 56, and zero for both the output indicator value Px and the load-response output value Pf means that the outdoor fan 56 is stopped.

[0083] Furthermore, the cycle load of the refrigeration cycle circuit 10 is estimated from the discharge refrigerant pressure of the compressor 11 detected, for example, by the refrigerant pressure sensor 74, and the larger the discharge refrigerant pressure, the larger the cycle load is determined to be. And the larger the discharge refrigerant pressure of the compressor 11, that is, the larger the cycle load, the larger the load-responding output value Pf is set to. The cycle load of the refrigeration cycle circuit 10 is, in other words, the load applied to the refrigeration cycle circuit 10 when the refrigeration cycle is being performed, and the cycle load of the refrigeration cycle circuit 10 can be expressed in units such as "kW". The cycle load of the refrigeration cycle circuit 10 is mainly determined from the discharge refrigerant pressure of the compressor 11, but it is also acceptable to take into account the refrigerant temperature and refrigerant pressure at various points in the refrigeration cycle circuit 10 in addition to the discharge refrigerant pressure of the compressor 11.

[0084] For example, if the air conditioning unit 8 does not provide air conditioning to the vehicle compartment 80, the refrigeration cycle circuit 10 does not perform cycle operation, and the compressor 11 is stopped. Therefore, the load-response output value Pf is set to zero. In other words, if the refrigeration cycle circuit 10 is not in cycle operation, the load-response output value Pf is set to zero. More specifically, cycle operation of the refrigeration cycle circuit 10 means that the refrigeration cycle is executed by circulating the refrigerant in the refrigeration cycle circuit 10. Therefore, cycle operation of the refrigeration cycle circuit 10 means that the refrigeration cycle is being executed in the refrigeration cycle circuit 10.

[0085] In step S03, the control device 70 sets the output instruction value Px to the larger of the load-dependent output value Pf and the predetermined lower output limit value P0. Since the control device 70 determines the output instruction value Px in this way, the control device 70 operates the outdoor fan 56 so that the output of the outdoor fan 56 does not fall below the predetermined lower limit value corresponding to the lower output limit value P0.

[0086] Furthermore, if the load-responding output value Pf is "Pf ≥ P0", the output instruction value Px is set to "Px = Pf". Therefore, in this step S03, the control device 70 adjusts the output of the outdoor fan 56 according to the cycle load of the refrigeration cycle circuit 10, within the range where the output of the outdoor fan 56 does not fall below the predetermined lower limit. More specifically, the control device 70 increases the output of the outdoor fan 56 as the cycle load of the refrigeration cycle circuit 10 increases, within the range where the output of the outdoor fan 56 does not fall below the predetermined lower limit.

[0087] The load-responsive output value Pf in step S03 is determined according to the cycle load, just like in step S02; therefore, the larger the cycle load, the larger the value.

[0088] Furthermore, the lower output limit P0 is a value set to prevent the outdoor fan 56 from freezing, and is experimentally set in advance to a value greater than zero and less than the maximum value of the load-responding output value Pf. For example, the lower output limit P0 is set to minimize the power consumption of the outdoor fan 56 operating in accordance with that lower output limit P0, and to prevent the outdoor fan 56 from freezing below freezing point when it is stopped. Once the output instruction value Px is determined in step S02 or step S03, the process returns to step S01.

[0089] Thus, when the outside temperature TAM is below the outside temperature threshold T1, the lower limit of the output P0 is "P0>0", so the output instruction value Px will be "Px>0" even if the load-dependent output value Pf is "Pf=0". Therefore, when the outside temperature TAM reaches a temperature at which the stopped outdoor fan 56 may freeze (specifically, a temperature below the outside temperature threshold T1), the control device 70 operates the outdoor fan 56 regardless of whether the refrigeration cycle circuit 10 is in cycle operation or not.

[0090] Furthermore, the processing in each step of Figure 6 described above constitutes a functional unit that realizes its respective function. The control device 70 is equipped with these functional units.

[0091] As described above, according to this embodiment, if the outside temperature TAM reaches a temperature at which the stopped outdoor fan 56 may freeze, the control device 70 operates the outdoor fan 56 regardless of whether the refrigeration cycle circuit 10 is in cycle operation or not.

[0092] Therefore, if the outside temperature TAM reaches a temperature at which the stopped outdoor fan 56 could freeze, the outdoor fan 56 will operate even if it is not necessary to circulate outside air to the outdoor heat exchanger 16. In short, in that case, the impeller of the outdoor fan 56 will rotate. This prevents the outdoor fan 56 from freezing, thus preventing malfunctions caused by freezing of the outdoor fan 56.

[0093] For example, as indicated by arrow B2 in Figure 4, it is conceivable that snow may be thrown up and fall onto the outdoor ventilation unit 56. Even in such a case, the outdoor ventilation unit 56 will operate regardless of whether the air conditioning unit 8 is providing air conditioning inside the vehicle compartment 80, thus preventing the outdoor ventilation unit 56 from freezing. Furthermore, the outdoor heat exchanger 16 can be installed in a horizontal or nearly horizontal position, for example, as shown in Figure 4, without having to consider whether or not the outdoor ventilation unit 56 is likely to be covered with snow, thus increasing the flexibility of the layout of the outdoor heat exchanger 16 and the outdoor ventilation unit 56.

[0094] (1) Furthermore, according to this embodiment, the refrigeration cycle circuit 10 is configured to switch between a first operation, which transfers heat from the first heat exchange unit 51 to the second heat exchange unit 52, and a second operation, which transfers heat from the second heat exchange unit 52 to the first heat exchange unit 51. This second operation is performed when the air conditioning unit 8 is in heating operation, and it is assumed that during heating operation, there is a possibility that the outdoor fan unit 56, which is in a stopped state, may freeze.

[0095] Therefore, the control process shown in Figure 6 is executed when there is a high need to prevent the outdoor fan 56 from freezing in a situation where the outdoor fan 56 is likely to freeze while stopped. In other words, the control process shown in Figure 6 can be effectively utilized compared to a configuration in which the refrigeration cycle circuit 10 does not switch to the second operation.

[0096] (2) Furthermore, according to this embodiment, the outdoor fan 56 operates according to the electrical signals output from the control device 70. Therefore, compared to, for example, the case in which the outdoor fan 56 is turned on and off with a switch, the operation of the outdoor fan 56 can be controlled more precisely.

[0097] (3) Furthermore, according to this embodiment, when the outside temperature TAM is less than or equal to the outside temperature threshold T1, the control device 70 adjusts the output of the outdoor fan 56 in accordance with the cycle load of the refrigeration cycle circuit 10, within a range in which the output of the outdoor fan 56 does not fall below a predetermined lower limit corresponding to the lower limit value P0. This makes it possible to adjust the output of the outdoor fan 56 in accordance with the cycle load of the refrigeration cycle circuit 10 and to operate the outdoor fan 56 to prevent freezing.

[0098] (Second Embodiment) Next, a second embodiment will be described. In this embodiment, the differences from the first embodiment described above will be mainly explained. Furthermore, parts that are the same as or equivalent to the above embodiment will be omitted or simplified in their description. The same applies to the descriptions of the embodiments described later.

[0099] As shown in Figure 7, in this embodiment, the air conditioning system 8 includes a battery heat transfer medium circuit 45 in addition to the configuration of the first embodiment. Furthermore, the refrigeration cycle circuit 10 of this embodiment includes a chiller expansion valve 26 and a battery chiller 27. In the description of this embodiment, the heat transfer medium circuit 40 will be referred to as the air conditioning heat transfer medium circuit 40 to distinguish it from the battery heat transfer medium circuit 45.

[0100] The chiller expansion valve 26 has a refrigerant inlet 261 through which the refrigerant from the refrigeration cycle circuit 10 flows in, and a refrigerant outlet 262 through which the refrigerant flows out. The refrigerant inlet 261 of the chiller expansion valve 26 is connected to the refrigerant outlet 162 of the outdoor heat exchanger 16, and the refrigerant outlet 262 of the chiller expansion valve 26 is connected to the refrigerant inlet 271 of the battery chiller 27.

[0101] The chiller expansion valve 26 is an electrically operated pressure reducing device similar to the cooling expansion valve 20, and the throttle opening of the chiller expansion valve 26 is increased or decreased according to a control signal from the control device 70. In other words, the chiller expansion valve 26 reduces the pressure of the refrigerant that flows into the chiller expansion valve 26 from the refrigerant inlet 261, and the reduced pressure of the refrigerant flows out from the refrigerant outlet 262 to the refrigerant inlet 271 of the battery chiller 27.

[0102] Furthermore, the chiller expansion valve 26, like the cooling expansion valve 20, is configured to be fully closed. In other words, the chiller expansion valve 26, like the cooling expansion valve 20, can be in both a pressure-regulating state and a fully closed state. When the chiller expansion valve 26 is fully closed, the flow of refrigerant from the outdoor heat exchanger 16 to the battery chiller 27 is cut off. When the chiller expansion valve 26 is open, i.e., in the pressure-regulating state, the refrigerant reduced in pressure by the chiller expansion valve 26 flows out from the refrigerant outlet 262 of the chiller expansion valve 26 and flows to the refrigerant inlet 271 of the battery chiller 27.

[0103] The battery chiller 27 has a refrigerant inlet 271 through which the refrigerant from the refrigeration cycle circuit 10 flows in, a refrigerant outlet 272 through which the refrigerant flows out, a heat medium inlet 273 through which the heat medium circulating in the battery heat medium circuit 45 flows in, and a heat medium outlet 274 through which the heat medium flows out. The battery chiller 27 is a heat exchanger that exchanges heat between the refrigerant from the refrigeration cycle circuit 10 and the heat medium from the battery heat medium circuit 45, and through the heat exchange between the refrigerant and the heat medium, it evaporates the refrigerant and cools the heat medium.

[0104] The refrigerant evaporated by the battery chiller 27 flows out from the refrigerant outlet 272, and at the same time, the heat transfer medium cooled by the battery chiller 27 flows out from the heat transfer medium outlet 274. The refrigerant outlet 272 of the battery chiller 27 is connected to the refrigerant inlet 241 of the accumulator 24. The battery chiller 27 is installed across the refrigeration cycle circuit 10 and the battery heat transfer medium circuit 45, and therefore constitutes a part of both the refrigeration cycle circuit 10 and the battery heat transfer medium circuit 45.

[0105] The battery heat transfer circuit 45 is provided to cool the battery 48, which is mounted on the vehicle 78 as a power source for the vehicle. This battery 48 is, for example, a rechargeable secondary battery, and generates heat during charging and discharging.

[0106] The battery heat transfer medium circuit 45, like the air conditioning heat transfer medium circuit 40, is a fluid circuit in which a liquid heat transfer medium circulates. In addition to the battery chiller 27 described above, the battery heat transfer medium circuit 45 includes a pump 46, a battery heat exchange unit 47, and piping connecting them.

[0107] The pump 46 of the battery heat transfer medium circuit 45 has an inlet 461 and a discharge port 462. The inlet 461 of the pump 46 is connected to the heat transfer medium outlet 472 of the battery heat exchange unit 47, and the discharge port 462 of the pump 46 is connected to the heat transfer medium inlet 273 of the battery chiller 27. The pump 46 of the battery heat transfer medium circuit 45 is an electric pump that pumps heat transfer medium, similar to the pump 41 of the air conditioning heat transfer medium circuit 40, and operates according to a control signal from the control device 70.

[0108] The pump 46 of the battery heat transfer medium circuit 45 draws the heat transfer medium into the pump 46 from the inlet 461 and discharges the drawn-in heat transfer medium from the discharge port 462 to the heat transfer medium inlet 273 of the battery chiller 27. As a result, the heat transfer medium circulates in the battery heat transfer medium circuit 45, enabling heat exchange between the battery chiller 27 and the battery heat exchange unit 47.

[0109] The battery heat exchange unit 47 is connected to the battery 48 and, for example, is integrated with the battery 48. The battery heat exchange unit 47 has a heat medium inlet 471 into which the heat medium of the battery heat medium circuit 45 flows, and a heat medium outlet 472 into which the heat medium flows out. The heat medium inlet 471 of the battery heat exchange unit 47 is connected to the heat medium outlet 274 of the battery chiller 27.

[0110] The battery heat exchange unit 47 exchanges heat between the heat transfer medium of the battery heat transfer medium circuit 45 and the battery 48. Specifically, the battery heat exchange unit 47 exchanges heat between the heat transfer medium that flows into the battery heat exchange unit 47 from the heat transfer medium inlet 471 and the battery 48, and this heat exchange cools the battery 48. After the heat exchange, the heat transfer medium flows out from the heat transfer medium outlet 472 of the battery heat exchange unit 47 and is sucked into the suction port 461 of the pump 46.

[0111] The air conditioning unit 8 of this embodiment, configured as described above, can perform cooling, heating, and dehumidifying operations, respectively, similar to the first embodiment. Furthermore, the air conditioning unit 8 of this embodiment can perform cooling or dehumidifying operations and battery cooling operations to cool the battery 48 simultaneously. Note that the operation of the outdoor fan 56 and the indoor air conditioning unit 60 is the same as in the first embodiment, even when battery cooling operations are performed simultaneously with cooling or dehumidifying operations.

[0112] For example, when the air conditioning unit 8 is in cooling operation, as shown in Figure 8, the control device 70 operates each component of the air conditioning unit 8, such as the heating expansion valve 14, the on / off valve 18, the cooling expansion valve 20, and the compressor 11, in the same manner as in the first embodiment. Furthermore, when battery cooling operation is performed simultaneously with the cooling operation, in addition to the operation of each component, the control device 70 also sets the chiller expansion valve 26 to a pressure adjustment state.

[0113] With these controls, when cooling operation and battery cooling operation are performed simultaneously, the refrigeration cycle circuit 10 enters cooling mode, and the refrigerant circulates in the refrigeration cycle circuit 10 as shown by the arrow FLc.

[0114] In other words, the refrigerant discharged from the outlet 112 of the compressor 11 flows through the path described in the first embodiment for cooling operation. In addition, the refrigerant flowing out from the refrigerant outlet 162 of the outdoor heat exchanger 16 flows not only to the cooling expansion valve 20 but also in parallel to the chiller expansion valve 26. The refrigerant that flows to the chiller expansion valve 26 then flows from the chiller expansion valve 26 through the battery chiller 27 to the refrigerant inlet 241 of the accumulator 24. Note that if the battery cooling operation of the air conditioning unit 8 is not performed, the chiller expansion valve 26 is kept in a fully closed state.

[0115] Furthermore, when the air conditioning unit 8 is operating in cooling mode and the battery cooling mode simultaneously, the pump 46 of the battery heat transfer medium circuit 45 is activated. As a result, the heat transfer medium circulates in the battery heat transfer medium circuit 45, allowing the refrigerant of the battery chiller 27 to exchange heat with the battery 48 via the heat transfer medium in the battery heat transfer medium circuit 45.

[0116] The operation of each component of the air conditioning system 8 cools the vehicle compartment 80, similar to the first embodiment. At the same time, the battery 48 is cooled by heat exchange between the refrigerant of the battery chiller 27 and the battery 48 via the heat transfer medium of the battery heat transfer medium circuit 45.

[0117] Furthermore, during heating operation of the air conditioning unit 8, the control device 70 completely closes the chiller expansion valve 26 and stops the pump 46 of the battery heat transfer medium circuit 45.

[0118] Except as described above, this embodiment is the same as the first embodiment. In this embodiment, the effects obtained from the configuration common to the first embodiment can be obtained in the same way as in the first embodiment.

[0119] (Third embodiment) Next, a third embodiment will be described. This embodiment will primarily describe the differences from the first embodiment described above.

[0120] As shown in Figure 9, in this embodiment, the air conditioning system 8 includes an outdoor heat transfer medium circuit 53 in addition to the configuration of the first embodiment. Furthermore, the refrigeration cycle circuit 10 in this embodiment does not include an outdoor heat exchanger 16 (see Figure 1), but instead includes a heat exchanger 29 for the heat transfer medium. For the purposes of this description, the heat transfer medium circuit 40 will be referred to as the air conditioning heat transfer medium circuit 40 to distinguish it from the outdoor heat transfer medium circuit 53.

[0121] The heat exchanger 29 for the heat transfer medium has a refrigerant inlet 291 through which the refrigerant from the refrigeration cycle circuit 10 flows in, a refrigerant outlet 292 through which the refrigerant flows out, a heat transfer medium inlet 293 through which the heat transfer medium circulating to the outdoor heat transfer medium circuit 53 flows in, and a heat transfer medium outlet 294 through which the heat transfer medium flows out.

[0122] The refrigerant inlet 291 of the heat exchanger 29 for the heat transfer medium is connected to the refrigerant outlet 142 of the heating expansion valve 14, and the refrigerant outlet 292 of the heat exchanger 29 for the heat transfer medium is connected to the refrigerant inlet 181 of the on / off valve 18 and the refrigerant inlet 201 of the cooling expansion valve 20, respectively. In addition, the heat transfer medium inlet 293 of the heat exchanger 29 for the heat transfer medium is connected to the heat transfer medium outlet 552 of the outdoor heat exchanger 55 included in the outdoor heat transfer medium circuit 53, and the heat transfer medium outlet 294 of the heat exchanger 29 for the heat transfer medium is connected to the suction port 541 of the pump 54 included in the outdoor heat transfer medium circuit 53.

[0123] The heat exchanger 29 for the heat transfer medium is a heat exchanger that exchanges heat between the refrigerant in the refrigeration cycle circuit 10 and the heat transfer medium in the outdoor heat transfer medium circuit 53. The heat exchanger 29 for the heat transfer medium is a heat exchanger that replaces the outdoor heat exchanger 16 (see Figure 1) of the first embodiment in the refrigeration cycle circuit 10. Therefore, when the refrigeration cycle circuit 10 is in cooling mode, the heat exchanger 29 for the heat transfer medium functions as a condenser that releases heat to the heat transfer medium and condenses the refrigerant through heat exchange between the heat transfer medium and the refrigerant in the outdoor heat transfer medium circuit 53. On the other hand, when the refrigeration cycle circuit 10 is in heating mode, the heat exchanger 29 for the heat transfer medium functions as an evaporator that absorbs heat from the heat transfer medium and evaporates the refrigerant through heat exchange between the heat transfer medium and the refrigerant in the outdoor heat transfer medium circuit 53.

[0124] Furthermore, since the heat exchanger 29 for the heat transfer medium is installed across the refrigeration cycle circuit 10 and the outdoor heat transfer medium circuit 53, it constitutes a part of the refrigeration cycle circuit 10 and a part of the outdoor heat transfer medium circuit 53. Also, the heat exchanger 29 for the heat transfer medium does not need to be installed in the same location as the outdoor heat exchanger 16 in the first embodiment (see Figures 1 and 4).

[0125] The outdoor heat transfer medium circuit 53 is a fluid circuit in which a liquid heat transfer medium circulates, similar to the air conditioning heat transfer medium circuit 40. In addition to the heat transfer medium heat exchanger 29 described above, the outdoor heat transfer medium circuit 53 includes a pump 54, an outdoor heat exchanger 55, and piping connecting them.

[0126] The pump 54 of the outdoor heat transfer medium circuit 53 has an inlet 541 and a discharge port 542, and the discharge port 542 of the pump 54 is connected to the heat transfer medium inlet 551 of the outdoor heat exchanger 55. The pump 54 of the outdoor heat transfer medium circuit 53 is an electric pump that pumps the heat transfer medium, similar to the pump 41 of the air conditioning heat transfer medium circuit 40, and operates according to a control signal from the control device 70.

[0127] The pump 54 of the outdoor heat transfer medium circuit 53 draws the heat transfer medium into the pump 54 from the intake port 541 and discharges the drawn-in heat transfer medium from the discharge port 542 to the heat transfer medium inlet 551 of the outdoor heat exchanger 55. As a result, the heat transfer medium circulates in the outdoor heat transfer medium circuit 53, enabling heat exchange between the heat transfer medium heat exchanger 29 and the outdoor heat exchanger 55.

[0128] The outdoor heat exchanger 55 is arranged in the vehicle 78 in the same manner as the outdoor heat exchanger 16 of the first embodiment (see Figure 1). That is, as shown in Figure 4, the outdoor heat exchanger 55 is located outside the passenger compartment 80, and is positioned in the same orientation and location as the outdoor heat exchanger 16 of the first embodiment within the vehicle 78.

[0129] Furthermore, the arrangement of the outdoor air blower 56 relative to the outdoor heat exchanger 55 in this embodiment is the same as the arrangement of the outdoor air blower 56 relative to the outdoor heat exchanger 16 in the first embodiment. Therefore, the air passing through the outdoor heat exchanger 55 flows from the bottom to the top, as shown by arrows A1 and A2 in Figure 4.

[0130] As shown in Figure 9, the outdoor heat exchanger 55 has a heat medium inlet 551 through which the heat medium from the outdoor heat medium circuit 53 flows in, and a heat medium outlet 552 through which the heat medium flows out. The outdoor heat exchanger 55 is a heat exchanger that performs heat exchange with the outside air.

[0131] In other words, the outdoor heat exchanger 55 exchanges heat between the outside air passing through the outdoor heat exchanger 55 and the heat transfer medium circulating within the outdoor heat exchanger 55. More specifically, when the refrigeration cycle circuit 10 is in cooling mode, the outdoor heat exchanger 55 functions as a heat radiator that releases heat to the outside air through heat exchange between the outside air and the heat transfer medium in the outdoor heat transfer medium circuit 53. On the other hand, when the refrigeration cycle circuit 10 is in heating mode, the outdoor heat exchanger 55 functions as a heat absorber that absorbs heat from the outside air through heat exchange between the outside air and the heat transfer medium in the outdoor heat transfer medium circuit 53.

[0132] As configured above, the air conditioning system 8 of this embodiment can perform cooling, heating, and dehumidifying operations, similar to the first embodiment. Whenever the compressor 11 of the refrigeration cycle circuit 10 is operated, regardless of whether the refrigeration cycle circuit 10 is in cooling mode or heating mode, the pump 54 of the outdoor heat transfer medium circuit 53 is also operated. As a result, the heat transfer medium circulates in the outdoor heat transfer medium circuit 53, and the refrigerant in the heat transfer medium heat exchanger 29 can exchange heat with the outside air passing through the outdoor heat exchanger 55 via the heat transfer medium in the outdoor heat transfer medium circuit 53.

[0133] In this embodiment, as in the first embodiment, the heat transfer medium circuit 40 and the indoor evaporator 22 of the air conditioning system 8 constitute a first heat exchange unit 51 that performs heat exchange between the blown air sent into the passenger compartment 80 and the refrigerant of the refrigeration cycle circuit 10.

[0134] In contrast, as can be seen from the above, the outdoor heat transfer medium circuit 53 exchanges heat between the refrigerant of the heat transfer medium heat exchanger 29 and the outside air passing through the outdoor heat exchanger 55 via the heat transfer medium. Therefore, in this embodiment, the outdoor heat transfer medium circuit 53, including the outdoor heat exchanger 55, functions as a second heat exchange unit that exchanges heat with the outside air.

[0135] Furthermore, the refrigeration cycle circuit 10 of this embodiment is configured to switch between a first operation, which is to transfer heat from the first heat exchange unit 51 to the outdoor heat transfer medium circuit 53, which is the second heat exchange unit, and a second operation, which is to transfer heat from the outdoor heat transfer medium circuit 53 to the first heat exchange unit 51.

[0136] Except as described above, this embodiment is the same as the first embodiment. In this embodiment, the effects obtained from the configuration common to the first embodiment can be obtained in the same way as in the first embodiment.

[0137] Although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with the second embodiment described above.

[0138] (Fourth Embodiment) Next, a fourth embodiment will be described. This embodiment will primarily describe the differences from the first embodiment described above.

[0139] Unlike the first embodiment, the outdoor ventilation unit 56 in this embodiment is not controlled by the control device 70. Therefore, the control device 70 in this embodiment does not perform the control processing shown in Figure 6. Instead, as shown in Figure 10, the air conditioning unit 8 in this embodiment is equipped with an operating switch 75 and a temperature switch 76.

[0140] The operating switch 75 is located in the first power supply path 751, which electrically connects the electric motor 561 of the outdoor fan 56 to, for example, the positive terminal of the power supply 82. The outdoor fan 56 has an electric motor 561 and an impeller connected to the electric motor 561. When the electric motor 561 is energized, it rotates the impeller, and the rotation of the impeller causes the outdoor fan 56 to circulate outside air to the outdoor heat exchanger 16. The power supply 82 is, for example, a vehicle battery. The first power supply path 751 is composed of, for example, busbars and electric wires.

[0141] The operating switch 75 disconnects the first power supply path 751 in accordance with the cycle load of the refrigeration cycle circuit 10. In other words, the operating switch 75 shuts off or enables the first power supply path 751 in accordance with the cycle load of the refrigeration cycle circuit 10.

[0142] For example, the operating switch 75 is a pressure switch that opens and closes in accordance with the refrigerant pressure at the discharge port 112 of the compressor 11 (i.e., the discharge refrigerant pressure of the compressor 11). More specifically, the operating switch 75 switches from off to on when the discharge refrigerant pressure of the compressor 11 exceeds a predetermined refrigerant pressure threshold. Since the discharge refrigerant pressure of the compressor 11 roughly corresponds to the cycle load of the refrigeration cycle circuit 10, as described above, the operating switch 75 can be said to open and close the first power supply path 751 in accordance with the cycle load of the refrigeration cycle circuit 10.

[0143] When the operating switch 75 is turned on, that is, when the operating switch 75 is closed, power is supplied from the power supply 82 to the electric motor 561 of the outdoor fan 56 via the first power supply path 751, and the outdoor fan 56 blows outside air to the outdoor heat exchanger 16.

[0144] Furthermore, for example, if the refrigeration cycle circuit 10 is not in cycle operation, the compressor 11 is stopped, and the refrigerant discharge pressure of the compressor 11 becomes significantly lower than the refrigerant pressure threshold. In that case, the operating switch 75 is turned off, and the first power supply path 751 is shut off.

[0145] The temperature switch 76 is located in the second power supply path 761. This second power supply path 761 is located in parallel with the first power supply path 751 and, like the first power supply path 751, electrically connects the electric motor 561 of the outdoor ventilation device 56 to, for example, the positive terminal of the power supply 82. The second power supply path 761 is composed of, for example, busbars and wires, similar to the first power supply path 751.

[0146] The temperature switch 76 disconnects the second power supply path 761 according to the ambient temperature TAM. For example, the temperature switch 76 can be configured as a thermostat or the like.

[0147] Specifically, the temperature switch 76 is configured to switch from off to on when the outside temperature TAM falls below a predetermined outside temperature threshold T1. That is, when the outside temperature TAM is below the outside temperature threshold T1, the temperature switch 76 electrically connects the outdoor fan 56 and the power supply 82 in the second power supply path 761.

[0148] When the temperature switch 76 is turned on due to a decrease in the outside temperature TAM, that is, when the temperature switch 76 is closed, power is supplied from the power supply 82 to the electric motor 561 of the outdoor fan 56 via the second power supply path 761, and the outdoor fan 56 blows outside air to the outdoor heat exchanger 16.

[0149] In this case, since the second power supply path 761 is in parallel with the first power supply path 751, when the temperature switch 76 is turned on, power is supplied from the power supply 82 to the electric motor 561 of the outdoor ventilation device 56, regardless of whether the operating switch 75 is on or off.

[0150] As described above, the temperature switch 76 in this embodiment operates on and off according to the outside temperature TAM, and functions as a fan control unit that controls the operation of the outdoor fan 56 according to the outside temperature TAM. And, as described above, the temperature switch 76, as a fan control unit, operates the outdoor fan 56 regardless of whether the operation switch 75 is on or off when the outside temperature TAM is below the outside temperature threshold T1. In other words, if the outside temperature TAM is at a temperature where the stopped outdoor fan 56 could freeze, the temperature switch 76 operates the outdoor fan 50 regardless of whether the refrigeration cycle circuit 10 is in cycle operation or not.

[0151] (1) As described above, according to this embodiment, the operating switch 75 disconnects the first power supply path 751, which electrically connects the outdoor fan 56 and the power supply 82, according to the cycle load of the refrigeration cycle circuit 10. The operating switch 75 shuts off the first power supply path 751 when the refrigeration cycle circuit 10 is not in cycle operation. On the other hand, the temperature switch 76 electrically connects the outdoor fan 56 and the power supply 82 in the second power supply path 761, which is provided in parallel with the first power supply path 751, when the outside temperature TAM is below the outside temperature threshold T1.

[0152] Therefore, with a simple electrical configuration, it is possible to activate the outdoor fan 56 regardless of whether the refrigeration cycle circuit 10 is in cycle operation or not, when the outside temperature TAM reaches a temperature at which the stopped outdoor fan 56 may freeze.

[0153] Except as described above, this embodiment is the same as the first embodiment. In this embodiment, the effects obtained from the configuration common to the first embodiment can be obtained in the same way as in the first embodiment.

[0154] Although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with the second or third embodiment described above.

[0155] (Other embodiments) (1) In each of the embodiments described above, the air conditioning system 8 is, for example, an air conditioning system installed in a hybrid vehicle, but this is just one example. The air conditioning system 8 may also be installed in a regular engine vehicle or an electric vehicle that is not a hybrid vehicle. Furthermore, the air conditioning system 8 may also be an air conditioning system installed in something other than a vehicle.

[0156] (2) In each of the embodiments described above, the outdoor air blower 56 is, for example, an axial flow fan, but it may be any other type of fan, such as a centrifugal fan.

[0157] (3) In the first embodiment described above, the refrigeration cycle circuit 10 has the circuit configuration shown in Figure 1, but this is just one example. The refrigeration cycle circuit 10 may have a circuit configuration other than the one shown in Figure 1, and may be switched between cooling mode and heating mode. Furthermore, the refrigeration cycle circuit 10 may have a circuit configuration that is exclusively for cooling mode and does not switch to heating mode.

[0158] (4) In each of the embodiments described above, the compressor 11 is an electric compressor, but this is just one example. The compressor 11 may also be a belt-driven compressor that is connected to an engine via a belt and driven by the power of that engine.

[0159] (5) The present disclosure is not limited to the embodiments described above and can be implemented in various modified forms. Furthermore, the embodiments described above are not unrelated to each other and can be combined as appropriate, except in cases where the combination is clearly impossible.

[0160] Furthermore, it goes without saying that, in each of the above embodiments, the elements constituting the embodiment are not necessarily essential unless explicitly stated to be particularly essential or unless they are clearly considered essential in principle. Also, in each of the above embodiments, when numerical values ​​such as the number, numerical values, quantities, or ranges of the components of the embodiment are mentioned, the embodiment is not limited to those specific numbers unless explicitly stated to be particularly essential or unless it is clearly limited to a specific number in principle. Also, in each of the above embodiments, when the material, shape, positional relationship, etc. of the components are mentioned, the embodiment is not limited to those material, shape, positional relationship, etc. unless explicitly stated or unless it is clearly limited to a specific material, shape, positional relationship, etc. in principle.

[0161] Furthermore, the control device 70 and its method described herein may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, the control device 70 and its method described herein may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the control device 70 and its method described herein may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. The computer program may also be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium.

Claims

1. An air conditioning system (8) that provides air conditioning inside the passenger compartment (80), A first heat exchange unit (51) that performs heat exchange with the air sent into the vehicle interior, The second heat exchange section (52, 53) includes an outdoor heat exchanger (16, 55) located outside the vehicle compartment that performs heat exchange with the outside air, A refrigeration cycle circuit (10) in which a refrigerant circulates with a phase change, and heat is transferred between the first heat exchange unit and the second heat exchange unit by a refrigeration cycle caused by the circulation of the refrigerant, An electric outdoor ventilation device (56) located outside the vehicle compartment that directs the outside air to the outdoor heat exchanger, If the ambient temperature (TAM) reaches a temperature at which the non-operating outdoor fan could freeze, the fan control unit (76) activates the outdoor fan regardless of whether the refrigeration cycle circuit is in cycle operation or not. The system includes a first power supply path (751) that electrically connects the outdoor air blower and the power supply (82), which is disconnected or opened according to the cycle load of the refrigeration cycle circuit, and an operating switch (75) that shuts off the first power supply path when the refrigeration cycle circuit is not in cycle operation. The airflow control unit is a temperature switch that connects and disconnects a second power supply path (761), which is provided in parallel with the first power supply path and electrically connects the outdoor air blower and the power supply, according to the temperature of the outside air. The temperature switch electrically connects the outdoor fan and the power supply in the second power supply path when the temperature of the outside air is below a predetermined outside temperature threshold (T1) in the air conditioning system.

2. An air conditioning system (8) that provides air conditioning inside the passenger compartment (80), A first heat exchange unit (51) that performs heat exchange with the air sent into the vehicle interior, The second heat exchange section (52, 53) includes an outdoor heat exchanger (16, 55) located outside the vehicle compartment that performs heat exchange with the outside air, A refrigeration cycle circuit (10) in which a refrigerant circulates with a phase change, and heat is transferred between the first heat exchange unit and the second heat exchange unit by a refrigeration cycle caused by the circulation of the refrigerant, An outdoor ventilation device (56) located outside the vehicle compartment that directs the outside air to the outdoor heat exchanger, The system includes a fan control unit (70) that activates the outdoor fan regardless of whether the refrigeration cycle circuit is in cycle operation, if the ambient temperature (TAM) is at a temperature at which the outdoor fan, which is not operating, could freeze. The air supply control unit adjusts the air supply output of the outdoor air supply device according to the cycle load of the refrigeration cycle circuit, within a range where the air supply output of the outdoor air supply device does not fall below a predetermined lower limit, when the temperature of the outside air is below a predetermined outside air temperature threshold (T1).

3. The air conditioning device according to claim 1 or 2, wherein the refrigeration cycle circuit is configured to switch between an operation to transfer heat from the first heat exchange unit to the second heat exchange unit and an operation to transfer heat from the second heat exchange unit to the first heat exchange unit.

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