Refrigeration cycle apparatus

Abstract

This refrigeration cycle apparatus is provided with a refrigeration cycle (10) having a compressor (11), a heating unit (20), a branch unit (13), an auxiliary heat dissipation unit (14), a first decompression unit (15a), a first evaporator (16), a second decompression unit (15b), and a second evaporator (17). The heating unit includes a radiator (12) for radiating the heat of a high-pressure refrigerant compressed by the compressor, and heats an object to be heated by the heat of the high-pressure refrigerant. The auxiliary heat dissipation unit dissipates heat from one of the refrigerants flowing out from the branch unit to an object to be dissipated. The first decompression unit decompresses the refrigerant flowing out from the auxiliary heat dissipation unit. The refrigeration cycle device has a heating mode and a cooling mode. The heating mode includes an operation mode in which inflow of the refrigerant to the auxiliary heat radiation unit is blocked as an operation mode for heating the object to be heated by using the refrigerant discharged from the compressor as a heat source. The cooling mode includes an operation mode in which inflow of the refrigerant to the second evaporator is blocked as an operation mode for cooling a first object to be cooled by the first evaporator.

Description

Refrigeration cycle equipment CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2024-075120 filed on May 7, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a refrigeration cycle device including a refrigeration cycle having a radiator and an auxiliary heat dissipation section.

[0003] BACKGROUND ART In a conventional refrigeration cycle device, a technique is known in which a radiator and an auxiliary radiator are disposed on the high-pressure side of the cycle and utilized to improve the cooling capacity of the refrigeration cycle.

[0004] For example, in the invention described in Patent Document 1, a sub-condenser that functions as an auxiliary heat dissipation section is placed downstream of a condenser that functions as a radiator, and by exchanging heat with the air, the degree of supercooling of the refrigerant flowing out of the condenser is increased, thereby improving cooling capacity.

[0005] Japanese Patent Application Laid-Open No. 2021-195116

[0006] In the configuration described in Patent Document 1, the heat dissipation objects in the condenser and sub-condenser are different, that is, the heat medium and air, and therefore the degree of subcooling of the refrigerant can be sufficiently increased, thereby improving the cooling capacity for the objects to be cooled (air and battery).

[0007] However, in the configuration described in Patent Document 1, there is a concern that heating capacity may decrease when attempting to heat a heating object on the high-pressure side of the refrigeration cycle. Specifically, in the configuration described in Patent Document 1, a sub-condenser, whose heat exchange object is air, is directly connected downstream of a condenser, whose heat exchange object is a heat medium. As a result, the refrigerant that has dissipated heat to the heat medium in the condenser necessarily exchanges heat with air in the sub-condenser. In this case, if the air temperature is low, the refrigerant may be cooled too much in the sub-condenser, which may increase the compression power in the refrigeration cycle.

[0008] In view of the above points, the present disclosure aims to provide a refrigeration cycle device that is equipped with a refrigeration cycle having a radiator and an auxiliary heat dissipation section, and that can exert heating and cooling capacities according to the environment and operating mode.

[0009] A refrigeration cycle device according to one aspect of the present disclosure includes a refrigeration cycle having a compressor, a heating section, a branching section, an auxiliary heat dissipation section, a first pressure reduction section, a first evaporator, a second pressure reduction section, and a second evaporator.

[0010] The compressor compresses and discharges the refrigerant. The heating unit includes a radiator that radiates heat from the high-pressure refrigerant compressed by the compressor, and heats an object to be heated using the heat of the high-pressure refrigerant. The branching unit branches the flow of refrigerant flowing out from the radiator. The auxiliary heat radiating unit radiates heat from one of the refrigerants flowing out from the branching unit to the object to be cooled. The first pressure reducing unit reduces the pressure of the refrigerant flowing out from the auxiliary heat radiating unit. The first evaporator evaporates the refrigerant depressurized in the first pressure reducing unit to cool the first object to be cooled. The second pressure reducing unit reduces the pressure of the other refrigerant flowing out from the branching unit. The second evaporator evaporates the refrigerant depressurized in the second pressure reducing unit to cool the second object to be cooled.

[0011] The refrigeration cycle device has a heating mode and a cooling mode. The heating mode is an operation mode in which a heating object is heated using a refrigerant discharged from a compressor as a heat source, and includes an operation mode in which the inflow of refrigerant to the auxiliary heat radiation part is blocked. The cooling mode is an operation mode in which a first cooling object is cooled by a first evaporator, and includes an operation mode in which the inflow of refrigerant to the second evaporator is blocked.

[0012] In this refrigeration cycle device, when operating in cooling mode, the flow of refrigerant into the second evaporator is blocked, so the refrigerant circulates through the refrigeration cycle by flowing in the order of the compressor, radiator, branching section, auxiliary heat radiator, first pressure reduction section, and first evaporator. Therefore, in the refrigeration cycle device in cooling mode, the auxiliary heat radiator radiates heat to the heat radiating object, increasing the degree of subcooling of the refrigerant flowing out of the radiator, thereby improving cooling capacity. In other words, the refrigeration cycle device in cooling mode can achieve higher cooling capacity by cooling the first cooling object in the first evaporator.

[0013] When the refrigeration cycle device is operated in heating mode, the refrigerant is blocked from flowing into the auxiliary heat dissipation section, and the refrigerant circulates through the refrigeration cycle by flowing through the compressor, radiator, branch section, second pressure reduction section, and second evaporator in that order. Here, when a mode of circulation via the auxiliary heat dissipation section is adopted, the influence of heat exchange with the heat dissipation object in the auxiliary heat dissipation section affects the compression power in the refrigeration cycle, and it is expected that if the temperature of the heat dissipation object is too low, the compression power will increase.

[0014] In this regard, in the refrigeration cycle device according to the present disclosure, the inflow of refrigerant to the auxiliary heat dissipation section is blocked in the heating mode, thereby suppressing the effect of the temperature of the heat dissipation object on the refrigerant, and the object to be heated can be heated with an appropriate compression power. In other words, the refrigeration cycle device can achieve heating capacity and cooling capacity according to the environment and operation mode when heating the object to be heated or cooling the first object to be cooled.

[0015] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0014] Fig. 1 is an overall configuration diagram of a vehicle air conditioner according to one embodiment; Fig. 2 is an overall configuration diagram of an interior air conditioning unit according to one embodiment; Fig. 3 is a block diagram showing a control system of a vehicle air conditioner according to one embodiment; Fig. 4 is an explanatory diagram showing a cooling mode in a vehicle air conditioner; Fig. 5 is an explanatory diagram showing a heating mode in a vehicle air conditioner; Fig. 6 is an explanatory diagram showing a dehumidifying heating mode in a vehicle air conditioner; Fig. 7 is a flowchart relating to operation mode switching control in a vehicle air conditioner; Fig. 8 is an explanatory diagram showing a battery cooling mode in a vehicle air conditioner; Fig. 9 is an explanatory diagram showing an air conditioning cooling mode in a vehicle air conditioner.

[0016] An embodiment of the present disclosure will be described with reference to the drawings. In this embodiment, a refrigeration cycle device according to the present disclosure is applied to a vehicle air conditioner 1 mounted on a vehicle. The vehicle air conditioner 1 conditions the air inside a vehicle cabin, which is a space to be air-conditioned in the vehicle, and adjusts the temperature of a battery 31 mounted on the vehicle.

[0017] The vehicle air conditioner 1 can switch between a cooling mode, a heating mode, and a dehumidifying and heating mode as air conditioning operation modes for air conditioning the vehicle cabin. The cooling mode is an operation mode in which the air blown into the vehicle cabin is cooled and then blown into the vehicle cabin. The heating mode is an operation mode in which the air blown into the vehicle cabin is heated and then blown into the vehicle cabin. The dehumidifying and heating mode is an operation mode in which the cooled and dehumidified air is reheated and then blown into the vehicle cabin, thereby dehumidifying and heating the vehicle cabin.

[0018] The refrigeration cycle 10 of the vehicle air conditioner 1 employs an HFO refrigerant (specifically, R1234yf) as a refrigerant. The refrigeration cycle 10 is a vapor compression subcritical refrigeration cycle in which the pressure of the high-pressure refrigerant discharged from the compressor 11 shown in FIG. 1 does not exceed the critical pressure of the refrigerant. Refrigeration oil (specifically, PAG oil) is mixed into the refrigerant to lubricate the compressor 11. A portion of the refrigeration oil circulates through the cycle together with the refrigerant.

[0019] Next, a specific configuration of the vehicle air conditioner 1 according to this embodiment will be described with reference to Figures 1 to 3. The vehicle air conditioner 1 according to this embodiment has a refrigeration cycle 10, a heating section 20, a low-temperature side heat medium circuit 30, an interior air conditioning unit 40, and a control device 50.

[0020] First, a description will be given of the components constituting the refrigeration cycle 10 of the vehicle air conditioner 1. The refrigeration cycle 10 is a vapor compression refrigeration cycle device. The refrigeration cycle 10 includes a compressor 11, a heat medium refrigerant heat exchanger 12, a branching section 13, a subcooler 14, a first expansion valve 15a, a second expansion valve 15b, an interior evaporator 16, a chiller 17, an evaporation pressure control valve 18, and a junction section 19.

[0021] The compressor 11 in the refrigeration cycle 10 draws in, compresses, and discharges refrigerant. The compressor 11 is located under the hood of the vehicle. The compressor 11 is an electric compressor that uses an electric motor to rotate a fixed-displacement compression mechanism with a fixed discharge capacity. The rotation speed (i.e., refrigerant discharge capacity) of the compressor 11 is controlled by a control signal output from a control device 50, which will be described later.

[0022] The discharge port of the compressor 11 is connected to an inlet side of a refrigerant passage 12a of the heat medium refrigerant heat exchanger 12. The heat medium refrigerant heat exchanger 12 is a heat exchanger that dissipates heat contained in the high-pressure refrigerant discharged from the compressor 11 to a high-temperature side heat medium circulating in a high-temperature side heat medium circuit 21 of the heating unit 20, thereby heating the high-temperature side heat medium.

[0023] The heat medium-refrigerant heat exchanger 12 has a refrigerant passage 12a through which the refrigerant of the refrigeration cycle 10 flows, and a heat medium passage 12b through which the high-temperature side heat medium of the high-temperature side heat medium circuit 21 flows. The heat medium-refrigerant heat exchanger 12 is formed of the same type of metal (aluminum alloy in this embodiment) that has excellent heat conductivity, and each component is integrated by brazing.

[0024] As a result, the high-pressure refrigerant flowing through the refrigerant passage 12a and the high-temperature heat medium flowing through the heat medium passage 12b can exchange heat with each other. The heat medium-refrigerant heat exchanger 12 is an example of a condenser and radiator that radiates heat from the high-pressure refrigerant, and constitutes a part of the heating unit 20 described below. The high-temperature heat medium flowing through the heat medium passage 12b can be a solution containing ethylene glycol, an antifreeze solution, or the like.

[0025] A branching section 13 having a three-way joint structure is connected to the outlet of the refrigerant passage 12a of the heat medium-refrigerant heat exchanger 12. The branching section 13 branches the flow of the liquid-phase refrigerant flowing out of the heat medium-refrigerant heat exchanger 12. The branching section 13 has three inlet / outlets, one of which serves as a refrigerant inlet and the other two of which serve as refrigerant outlets.

[0026] One refrigerant outlet of the branch section 13 is connected to the refrigerant inlet side of the sub-cooler 14. The other refrigerant outlet of the branch section 13 is connected to the refrigerant inlet side of the chiller 17 via a second expansion valve 15b.

[0027] The subcooler 14 is a heat exchanger that dissipates heat from the refrigerant flowing out from the heat medium refrigerant heat exchanger 12 and the branching portion 13 to the outside air, which is a heat dissipation target, to subcool the refrigerant. Therefore, in this embodiment, the subcooler 14 serves as an auxiliary heat dissipation portion that increases the degree of subcooling of the refrigerant flowing out from the heat medium refrigerant heat exchanger 12, which is a radiator. The refrigerant outlet of the subcooler 14 is connected to the refrigerant inlet side of the indoor evaporator 16 via a first expansion valve 15a.

[0028] The first expansion valve 15a is a pressure reducing section that reduces the pressure of the refrigerant flowing out from one refrigerant outlet of the branch section 13 and the sub-cooler 14. The first expansion valve 15a is an electric variable throttle mechanism that includes a valve body and an electric actuator. That is, the first expansion valve 15a is a so-called electric expansion valve.

[0029] The valve element of the first expansion valve 15a is configured to change the passage opening (i.e., the throttle opening) of the refrigerant passage. The electric actuator has a stepping motor that changes the throttle opening of the valve element. The operation of the first expansion valve 15a is controlled by a control signal output from the control device 50.

[0030] The first expansion valve 15a is configured as a variable throttle mechanism that has a full opening function that fully opens the refrigerant passage when the throttle opening is fully opened, and a full closing function that closes the refrigerant passage when the throttle opening is fully closed. In other words, the first expansion valve 15a can prevent the refrigerant from decompressing by fully opening the refrigerant passage.

[0031] The first expansion valve 15a closes the refrigerant passage, thereby blocking the inflow of refrigerant into the indoor evaporator 16. That is, the first expansion valve 15a functions both as a pressure reducing unit that reduces the pressure of the refrigerant and as a refrigerant circuit switching unit that switches the refrigerant circuit.

[0032] The outlet of the first expansion valve 15a is connected to the refrigerant inlet side of the indoor evaporator 16. The indoor evaporator 16 is an evaporator that, at least in the cooling mode, exchanges heat between the low-pressure refrigerant decompressed by the first expansion valve 15a and the blown air W to evaporate the low-pressure refrigerant and cool the blown air W.

[0033] 2, the interior evaporator 16 is disposed in a casing 41 of the interior air-conditioning unit 40. That is, the interior evaporator 16 corresponds to an example of a first evaporator that absorbs heat from the blown air W as a first object to be cooled, and the first expansion valve 15a corresponds to an example of a first pressure reducing section. The blown air W cooled by the interior evaporator 16 corresponds to an example of the first object to be cooled.

[0034] As described above, the second expansion valve 15b is connected to the other refrigerant outlet of the branch portion 13. The second expansion valve 15b is a pressure reducing portion that reduces the pressure of the refrigerant flowing out from the other refrigerant outlet of the branch portion 13, at least in the heating mode.

[0035] The second expansion valve 15b is an electric variable throttle mechanism, similar to the first expansion valve 15a, and includes a valve body and an electric actuator. That is, the second expansion valve 15b is a so-called electric expansion valve, and has a fully open function and a fully closed function.

[0036] In other words, the second expansion valve 15b can prevent the refrigerant from decompressing by fully opening the refrigerant passage, and can also block the inflow of refrigerant to the chiller 17 by closing the refrigerant passage. In other words, the second expansion valve 15b functions both as a pressure reducing unit that reduces the pressure of the refrigerant and as a refrigerant circuit switching unit that switches the refrigerant circuit.

[0037] The outlet of the second expansion valve 15b is connected to the refrigerant inlet side of the chiller 17. The chiller 17 is a heat exchanger that exchanges heat between the low-pressure refrigerant decompressed by the second expansion valve 15b and the low-temperature side heat medium circulating through the low-temperature side heat medium circuit 30.

[0038] The chiller 17 has a refrigerant passage 17a through which the low-pressure refrigerant decompressed by the second expansion valve 15b flows, and a heat medium passage 17b through which the low-temperature heat medium circulating in the low-temperature heat medium circuit 30 flows. Therefore, the chiller 17 is an evaporator that evaporates the low-pressure refrigerant and absorbs heat from the low-temperature heat medium by heat exchange between the low-pressure refrigerant flowing through the refrigerant passage 17a and the low-temperature heat medium flowing through the heat medium passage 17b. That is, the chiller 17 corresponds to an example of a second evaporator, and the second expansion valve 15b corresponds to an example of a second pressure reduction section. The low-temperature heat medium cooled by the chiller 17 corresponds to an example of a second object to be cooled in this embodiment.

[0039] 1, the inlet side of an evaporation pressure regulating valve 18 is connected to the refrigerant outlet of the interior evaporator 16. The evaporation pressure regulating valve 18 is an evaporation pressure adjusting unit that maintains the refrigerant evaporation pressure in the interior evaporator 16 at or above a predetermined reference pressure. The evaporation pressure regulating valve 18 is configured as a mechanical variable throttle mechanism that increases the valve opening degree as the refrigerant pressure on the outlet side of the interior evaporator 16 increases.

[0040] The evaporation pressure regulating valve 18 is configured to maintain the refrigerant evaporation temperature in the indoor evaporator 16 at a reference temperature (1° C. in this embodiment) or higher that can prevent frost from forming on the indoor evaporator 16.

[0041] One refrigerant inlet of the confluence section 19 is connected to the outlet of the evaporation pressure adjustment valve 18. The other refrigerant inlet of the confluence section 19 is connected to the refrigerant outlet of the chiller 17. The confluence section 19 has a three-way joint structure similar to that of the branch section 13, with two of the three inlet and outlet ports serving as refrigerant inlets and the remaining one serving as a refrigerant outlet.

[0042] The confluence section 19 merges the refrigerant flowing out from the evaporation pressure adjustment valve 18 and the refrigerant flowing out from the chiller 17. The refrigerant outlet of the confluence section 19 is connected to the suction port side of the compressor 11.

[0043] 1 , in the refrigeration cycle 10 according to this embodiment, the subcooler 14, the first expansion valve 15a, the indoor evaporator 16, and the evaporation pressure control valve 18 are arranged between one refrigerant outlet of the branching section 13 and one refrigerant inlet of the merging section 19. Therefore, the flow rate of the refrigerant circulating through the subcooler 14 can be adjusted by adjusting the throttle opening of the first expansion valve 15a. When the refrigerant flows through the subcooler 14, heat is released from the refrigerant, and the refrigerant becomes a complete liquid phase, making it easier to control the state of the refrigerant circulating through the refrigeration cycle 10. The first expansion valve 15a corresponds to an example of a flow rate adjustment section.

[0044] Next, a description will be given of the heating unit 20 in the vehicle air conditioner 1. The heating unit 20 is configured to heat the blown air W supplied to the air-conditioned space using the high-pressure refrigerant in the refrigeration cycle 10 as a heat source. That is, the object to be heated in this embodiment includes the blown air W supplied to the air-conditioned space.

[0045] The heating unit 20 according to this embodiment is configured by a high-temperature side heat medium circuit 21. The high-temperature side heat medium circuit 21 is a heat medium circuit that circulates a high-temperature side heat medium, and as the high-temperature side heat medium, a solution containing ethylene glycol, an antifreeze solution, or the like can be used.

[0046] The high-temperature side heat medium circuit 21 of the heating section 20 is arranged with the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12, a radiator 22, a heater core 23, an electric heater 24, a high-temperature side flow control valve 25, a high-temperature side pump 26, etc.

[0047] As described above, in the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12, the high-temperature side heat medium is heated by heat exchange with the high-pressure refrigerant flowing through the refrigerant passage 12a. That is, the high-temperature side heat medium is heated using the heat pumped up by the refrigeration cycle 10. Therefore, the object to be heated in this embodiment also includes the high-temperature side heat medium circulating through the high-temperature side heat medium circuit 21.

[0048] The radiator 22 is a heat exchanger that exchanges heat between the high-temperature side heat medium heated by the heat medium-refrigerant heat exchanger 12 or the like and the outside air OA blown by an outside air fan (not shown), thereby radiating the heat of the high-temperature side heat medium to the outside air OA. The radiator 22 corresponds to an example of an outside air radiator.

[0049] The radiator 22 is disposed at the front side inside the vehicle hood. As the above-described outside air fan is operated, outside air OA flows from the front side of the vehicle to the rear and passes through the heat exchange portion of the radiator 22. When the vehicle is traveling, airflow from the front side of the vehicle to the rear side can be directed onto the radiator 22.

[0050] The heater core 23 is a heat exchanger that exchanges heat between the high-temperature heat medium heated in the heat medium-refrigerant heat exchanger 12 or the like and the blown air W that has passed through the indoor evaporator 16, thereby heating the blown air W. Therefore, the heater core 23 corresponds to an example of a heating heat exchanger. As shown in Figures 1 and 2, the heater core 23 is disposed in a casing 41 of the indoor air conditioning unit 40.

[0051] An electric heater 24 is connected to one inlet / outlet of the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12. The electric heater 24 is a heating device that generates heat when supplied with electric power and heats the high-temperature side heat medium flowing through the heat medium passage of the electric heater 24.

[0052] For example, a PTC heater having a PTC element (i.e., a positive temperature coefficient thermistor) can be used as the electric heater 24. The electric heater 24 can arbitrarily adjust the amount of heat for heating the high-temperature side heat medium by a control voltage output from the control device 50.

[0053] One of the inlet and outlet ports of the high-temperature side flow control valve 25 is connected to the outlet side of the heat medium passage of the electric heater 24. The high-temperature side flow control valve 25 is configured as an electric three-way flow control valve having three inlet and outlet ports. The other of the inlet and outlet ports of the high-temperature side flow control valve 25 is connected to the inlet port of the heater core 23. The remaining inlet and outlet port of the high-temperature side flow control valve 25 is connected to the inlet port of the radiator 22.

[0054] Therefore, in the high-temperature side heat medium circuit 21, the radiator 22 and the heater core 23 are connected in parallel with respect to the flow of the high-temperature side heat medium passing through the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12. The high-temperature side flow control valve 25 can continuously adjust the flow rate ratio between the flow rate of the high-temperature side heat medium flowing into the heater core 23 and the flow rate of the high-temperature side heat medium flowing into the radiator 22 in the high-temperature side heat medium circuit 21.

[0055] A confluence portion of a three-way joint structure is connected to the outlet of the radiator 22 and the outlet of the heater core 23. The confluence portion uses one of the three inlet / outlet ports of the three-way joint structure as an outlet and the remaining two as inlet / outlets. Therefore, the confluence portion can merge the flow of high-temperature side heat medium that has passed through the radiator 22 and the flow of high-temperature side heat medium that has passed through the heater core 23.

[0056] The outlet at the junction is connected to the suction port of the high-temperature side pump 26. The high-temperature side pump 26 is a heat medium pump that pumps the high-temperature side heat medium in order to circulate it in the high-temperature side heat medium circuit 21. The high-temperature side pump 26 is an electric pump whose rotation speed (i.e., pumping capacity) is controlled by a control voltage output from the control device 50. The discharge port of the high-temperature side pump 26 is connected to the inlet / outlet on the other side of the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12.

[0057] As shown in FIG. 1 , the high-temperature side heat medium circuit 21 can continuously adjust the flow rate of the high-temperature side heat medium flowing toward the radiator 22 side and the flow rate of the high-temperature side heat medium flowing toward the heater core 23 side by using the high-temperature side flow control valve 25 arranged at the branching section.

[0058] In other words, by controlling the operation of the high-temperature side flow control valve 25, it is possible to adjust the amount of heat of the high-temperature side heat medium radiated to the outside air OA by the radiator 22 and the amount of heat of the high-temperature side heat medium radiated to the blown air W by the heater core 23.

[0059] Next, a description will be given of the low-temperature side heat medium circuit 30 in the vehicle air conditioner 1. The low-temperature side heat medium circuit 30 is a heat medium circuit that circulates a low-temperature side heat medium. As the low-temperature side heat medium, a fluid similar to the high-temperature side heat medium in the high-temperature side heat medium circuit 21 can be used.

[0060] The low-temperature side heat medium circuit 30 is arranged with the heat medium passage 17b of the chiller 17, a battery 31, an outside air heat exchanger 32, a low-temperature side flow rate adjustment valve 33, and a low-temperature side pump 34. The outlet of the heat medium passage 17b of the chiller 17 is connected to the suction port side of the low-temperature side pump 34.

[0061] The low-temperature side pump 34 is a heat medium pump that pumps the low-temperature side heat medium that has passed through the heat medium passage 17b of the chiller 17 in the low-temperature side heat medium circuit 30. The basic configuration of the low-temperature side pump 34 is similar to that of the high-temperature side pump 26.

[0062] A branching section having a three-way joint structure is connected to the discharge port side of the low-temperature side pump 34. The branching section uses one of the three inlet / outlet ports of the three-way joint structure as an inlet and the remaining two as outlet ports. Therefore, the branching section can branch the flow of the low-temperature side heat medium pumped from the low-temperature side pump 34 into two flows.

[0063] One outlet of the branched portion of the low-temperature side heat medium circuit 30 is connected to an inlet side of a heat medium passage of a battery 31. The battery 31 supplies power to various electrical devices of the vehicle and is, for example, a rechargeable secondary battery (in this embodiment, a lithium ion battery). The battery 31 generates heat during charging and discharging, and is therefore an example of a heat-generating device.

[0064] The battery 31 is a so-called assembled battery formed by stacking multiple battery cells and electrically connecting these battery cells in series or parallel. This type of battery 31 is prone to a decrease in output at low temperatures and to accelerated deterioration at high temperatures. For this reason, the temperature of the battery 31 must be maintained within an appropriate temperature range (e.g., 15°C or higher and 55°C or lower) that allows the charge / discharge capacity of the battery 31 to be fully utilized.

[0065] In the vehicle air conditioner 1, the heat medium passage for the battery 31 is formed in a battery case that houses the main body of the battery 31 configured as a battery pack. By passing the low-temperature side heat medium through the heat medium passage of the battery 31 to perform heat exchange, the heat generated in the battery 31 is absorbed by the low-temperature side heat medium, thereby adjusting the temperature of the battery 31. In other words, the battery 31 is connected to the low-temperature side heat medium circuit 30 so that it can be cooled by the low-temperature side heat medium, and the temperature of the battery 31 can be maintained within a predetermined temperature range.

[0066] The other outlet of the branched portion of the low-temperature side heat medium circuit 30 is connected to the inlet side of an outdoor air heat exchanger 32. The outdoor air heat exchanger 32 is a heat exchanger that exchanges heat between the low-temperature side heat medium discharged from the low-temperature side pump 34 and outdoor air OA blown by an outdoor air fan (not shown).

[0067] The outside-air heat exchanger 32 is disposed at the front side of the drive unit compartment. Therefore, when the vehicle is traveling, traveling wind can be applied to the outside-air heat exchanger 32. Therefore, the outside-air heat exchanger 32 may be formed integrally with the radiator 22 or the like.

[0068] 1, a low-temperature side flow rate adjustment valve 33 is connected to the outlet side of the heat medium passage of the battery 31 and the outlet side of the outside-air heat exchanger 32. The low-temperature side flow rate adjustment valve 33 is configured as an electric three-way flow rate adjustment valve having three inlet and outlet ports.

[0069] That is, one of the inlet / outlet ports of the low-temperature side flow rate adjustment valve 33 is connected to the outlet side of the heat medium passage of the battery 31, and another of the inlet / outlet ports of the low-temperature side flow rate adjustment valve 33 is connected to the outlet side of the outside-air heat exchanger 32. Another of the inlet / outlet ports of the low-temperature side flow rate adjustment valve 33 is connected to the inlet side of the heat medium passage 17b of the chiller 17.

[0070] Therefore, the low-temperature side heat medium circuit 30 can switch the flow of the low-temperature side heat medium in the low-temperature side heat medium circuit 30 by controlling the operation of the low-temperature side flow rate adjustment valve 33. For example, with regard to the flow of the low-temperature side heat medium passing through the heat medium passage 17b of the chiller 17, the low-temperature side flow rate adjustment valve 33 can continuously adjust the flow rate ratio between the flow rate of the low-temperature side heat medium passing through the outside-air heat exchanger 32 and the flow rate of the low-temperature side heat medium passing through the heat medium passage of the battery 31.

[0071] For example, in the low-temperature side heat medium circuit 30, the low-temperature side flow rate adjustment valve 33 can be controlled so that the inlet / outlet on the chiller 17 side communicates with the inlet / outlet on the battery 31 side and the inlet / outlet on the outside-air heat exchanger 32 side is closed. In this case, the flow of the low-temperature side heat medium is switched so that the entire amount of the low-temperature side heat medium that has passed through the chiller 17 passes through the heat medium passage of the battery 31.

[0072] According to this aspect, the low-temperature side heat medium cooled by the chiller 17 can be supplied to the battery 31, thereby cooling the battery 31. In other words, the waste heat of the battery 31, which is absorbed as the battery 31 is cooled, can be absorbed by the low-pressure refrigerant of the refrigeration cycle 10 through heat exchange in the chiller 17.

[0073] Furthermore, in the low-temperature side heat medium circuit 30, the low-temperature side flow rate adjustment valve 33 can be controlled to communicate the inlet / outlet on the chiller 17 side with the inlet / outlet on the outside-air heat exchanger 32 side and to close the inlet / outlet on the battery 31 side. In this case, the flow of the low-temperature side heat medium is switched so that the entire amount of the low-temperature side heat medium that has passed through the chiller 17 passes through the outside-air heat exchanger 32.

[0074] According to this aspect, the low-temperature side heat medium cooled by the chiller 17 can be supplied to the outside air heat exchanger 32, so that if the temperature of the low-temperature side heat medium is lower than the outside air temperature, heat can be absorbed from the outside air OA, thereby making it possible to use the outside air OA as a heat source.

[0075] That is, the vehicle air conditioner 1 can cool and regulate the temperature of the battery 31 by using the low-temperature side heat medium circuit 30. Furthermore, the vehicle air conditioner 1 can use the outside air OA as a heat source by using the outside air heat exchanger 32.

[0076] Next, the interior air conditioning unit 40 constituting the vehicle air conditioner 1 will be described with reference to Fig. 2. The interior air conditioning unit 40 is a unit in the vehicle air conditioner 1 for blowing out the blown air W, whose temperature has been adjusted by the refrigeration cycle 10, to an appropriate location within the vehicle cabin. The interior air conditioning unit 40 is disposed inside the instrument panel at the front end of the vehicle cabin.

[0077] The interior air conditioning unit 40 is configured by accommodating a blower 42, the interior evaporator 16, the heater core 23, etc. in an air passage formed inside a casing 41 that forms the outer shell of the unit. The casing 41 forms an air passage for the ventilation air W that is blown into the vehicle cabin. The casing 41 is molded from a resin (specifically, polypropylene) that has a certain degree of elasticity and excellent strength.

[0078] 2, an inside / outside air switching device 43 is disposed on the most upstream side of the blown air flow of the casing 41. The inside / outside air switching device 43 switches between introducing inside air (air inside the vehicle cabin) and outside air (air outside the vehicle cabin) into the casing 41.

[0079] The inside / outside air switching device 43 continuously adjusts the opening areas of the inside air inlet, which introduces inside air, and the outside air inlet, which introduces outside air, into the casing 41, using an inside / outside air switching door, thereby changing the ratio of the amount of inside air introduced to the amount of outside air introduced. The inside / outside air switching door is driven by an electric actuator for the inside / outside air switching door. The operation of this electric actuator is controlled by a control signal output from the control device 50.

[0080] A blower 42 is disposed downstream of the inside / outside air switching device 43 in the flow of blown air. The blower 42 is an electric blower that drives a centrifugal multi-blade fan with an electric motor. The blower 42 blows air drawn in through the inside / outside air switching device 43 toward the vehicle interior. The rotation speed (i.e., blowing capacity) of the blower 42 is controlled by a control voltage output from the control device 50.

[0081] The interior evaporator 16 and the heater core 23 are arranged in this order with respect to the flow of the air blown by the blower 42. In other words, the interior evaporator 16 is arranged upstream of the heater core 23 with respect to the flow of the air blown.

[0082] A cool air bypass passage 45 is formed within the casing 41. The cool air bypass passage 45 is an air passage that allows the blown air W that has passed through the interior evaporator 16 to bypass the heater core 23 and flow downstream.

[0083] An air mix door 44 is disposed downstream of the interior evaporator 16 in the flow of blown air and upstream of the heater core 23. The air mix door 44 adjusts the ratio of the amount of blown air W passing through the heater core 23 and the amount of blown air W passing through the cool air bypass passage 45 after passing through the interior evaporator 16.

[0084] The air mix door 44 is driven by an electric actuator for driving the air mix door, and the operation of this electric actuator is controlled by a control signal output from a control device 50.

[0085] A mixing space 46 is provided downstream of the heater core 23 in the flow of blown air. In the mixing space 46, the blown air W heated by the heater core 23 and the blown air W that has passed through the cool air bypass passage 45 and has not been heated by the heater core 23 are mixed.

[0086] Furthermore, openings for blowing out the blown air (conditioned air) mixed in the mixing space 46 into the vehicle compartment are arranged at the most downstream portion of the casing 41 in the blown air flow direction. These openings include a face opening, a foot opening, and a defroster opening (none of which are shown).

[0087] The face opening is an opening for blowing conditioned air toward the upper bodies of occupants in the vehicle cabin, the foot opening is an opening for blowing conditioned air toward the feet of occupants, and the defroster opening is an opening for blowing conditioned air toward the inside surface of the window glass at the front of the vehicle.

[0088] These face opening holes, foot opening holes, and defroster opening holes are connected to face air outlets, foot air outlets, and defroster air outlets (none of which are shown) provided in the vehicle cabin via ducts that form air passages, respectively.

[0089] Therefore, the temperature of the conditioned air mixed in the mixing space 46 is adjusted by the air mix door 44 adjusting the ratio of the air volume passing through the heater core 23 to the air volume passing through the cold air bypass passage 45. This also adjusts the temperature of the blown air (conditioned air) blown into the vehicle compartment from each air outlet.

[0090] A face door, a foot door, and a defroster door (none of which are shown) are disposed upstream of the face opening, foot opening, and defroster opening in the flow of blown air, respectively. The face door adjusts the opening area of ​​the face opening. The foot door adjusts the opening area of ​​the foot opening. The defroster door adjusts the opening area of ​​the defroster opening.

[0091] The face door, foot door, and defroster door constitute an air outlet mode switching device that switches the air outlet from which conditioned air is blown out. The face door, foot door, and defroster door are connected to an electric actuator for driving the air outlet mode door via a link mechanism or the like, and are rotated in conjunction with each other. The operation of this electric actuator is controlled by a control signal output from the control device 50.

[0092] Next, a control system of the vehicle air conditioner 1 according to this embodiment will be described with reference to Fig. 3. The control device 50 is composed of a well-known microcomputer including a CPU, ROM, RAM, etc., and its peripheral circuits.

[0093] The control device 50 performs various calculations and processes based on the control programs stored in its ROM, and controls the operation of various controlled devices connected to its output side, including the compressor 11, the first expansion valve 15a, the second expansion valve 15b, the electric heater 24, the high-temperature side flow control valve 25, the high-temperature side pump 26, the low-temperature side flow control valve 33, the low-temperature side pump 34, the blower 42, etc.

[0094] 3, a group of sensors for controlling air conditioning is connected to the input side of the control device 50. The group of sensors for controlling air conditioning includes an inside air temperature sensor 52a, an outside air temperature sensor 52b, a solar radiation sensor 52c, a high pressure sensor 52d, an evaporator temperature sensor 52e, a blown air temperature sensor 52f, and a battery temperature sensor 52g. Detection signals from these sensors for controlling air conditioning are input to the control device 50.

[0095] The inside air temperature sensor 52a is an inside air temperature detector that detects the temperature inside the vehicle cabin (inside air temperature) Tr. The outside air temperature sensor 52b is an outside air temperature detector that detects the temperature outside the vehicle cabin (outside air temperature) Tam. The solar radiation sensor 52c is an solar radiation amount detector that detects the amount of solar radiation As irradiating the vehicle cabin. The high-pressure sensor 52d is a refrigerant pressure detector that detects the high-pressure refrigerant pressure Pd in ​​the refrigerant flow path from the discharge port side of the compressor 11 to the inlet side of the first expansion valve 15a or the second expansion valve 15b.

[0096] The evaporator temperature sensor 52e is an evaporator temperature detector that detects the refrigerant evaporation temperature (evaporator temperature) Tefin in the interior evaporator 16. The blown air temperature sensor 52f is a blown air temperature detector that detects the blown air temperature TAV blown into the vehicle cabin. The battery temperature sensor 52g is a battery temperature detector that detects the battery temperature TBA, which is the temperature of the battery 31.

[0097] The battery temperature sensor 52g has multiple temperature detection units and detects the temperatures at multiple locations on the battery 31. This allows the control device 50 to detect the temperature difference between the various locations on the battery 31. Furthermore, the average value of the detected values ​​from the multiple temperature detection units is used as the battery temperature TBA.

[0098] A plurality of heat medium temperature sensors are connected to the input side of the control device 50 in order to detect the temperature of the heat medium in each of the high-temperature side heat medium circuit 21 and the low-temperature side heat medium circuit 30. The plurality of heat medium temperature sensors include a first heat medium temperature sensor 53a to a fifth heat medium temperature sensor 53e.

[0099] The first heat medium temperature sensor 53a is disposed at the outlet of the heat medium passage of the electric heater 24 and detects the temperature of the high-temperature side heat medium flowing out from the electric heater 24. The second heat medium temperature sensor 53b is disposed at the outlet of the radiator 22 and detects the temperature of the high-temperature side heat medium that has passed through the radiator 22. The third heat medium temperature sensor 53c is disposed at the inlet of the heater core 23 and detects the temperature of the high-temperature side heat medium flowing into the heater core 23.

[0100] The fourth heat medium temperature sensor 53d is arranged at the outlet of the heat medium passage 17b of the chiller 17, and detects the temperature of the low-temperature side heat medium flowing out from the chiller 17. The fifth heat medium temperature sensor 53e is arranged at the outlet of the heat medium passage of the battery 31, and detects the temperature of the low-temperature side heat medium flowing out from the heat medium passage of the battery 31.

[0101] The vehicle air conditioner 1 can then refer to the detection results of the first to fifth heat medium temperature sensors 53 a to 53 e to switch the flow of heat medium in the high-temperature side heat medium circuit 21 and the low-temperature side heat medium circuit 30 of the heating unit 20. This allows the vehicle air conditioner 1 to manage heat in the vehicle using the high-temperature side heat medium and the low-temperature side heat medium.

[0102] Furthermore, an operation panel 51, which is located near the instrument panel at the front of the vehicle interior, is connected to the input side of the control device 50. A plurality of operation switches are arranged on the operation panel 51. Therefore, operation signals from the plurality of operation switches are input to the control device 50. The various operation switches on the operation panel 51 include an auto switch, an air conditioning switch, an air volume setting switch, a temperature setting switch, etc.

[0103] The auto switch is operated to set or cancel automatic control operation of the automotive air conditioner 1. The cooling switch is operated to request cooling of the vehicle cabin. The air volume setting switch is operated to manually set the air volume of the blower 42. And the temperature setting switch is operated to set a target temperature Tset for the vehicle cabin.

[0104] In the control device 50, a control unit that controls various controlled devices connected to its output side is integrally configured, and the configuration (hardware and software) that controls the operation of each controlled device constitutes the control unit that controls the operation of each controlled device. For example, in the control device 50, the configuration that controls switching of the air conditioning operation mode in accordance with the outside air temperature during automatic control operation of the vehicle air conditioner 1 is the operation mode control unit 50a.

[0105] The control device 50 includes an electric heater control unit 50b that controls the heat output of the electric heater 24 that heats the high-temperature side heat medium. The control device 50 also includes a heat exchange amount adjustment control unit 50c that controls the operation of the low-temperature side flow rate adjustment valve 33, which is a heat exchange amount adjustment unit of the low-temperature side heat medium circuit 30.

[0106] Next, a description will be given of the operation of the vehicle air conditioner 1 according to this embodiment. As described above, the vehicle air conditioner 1 according to this embodiment can switch between a plurality of operation modes as needed, and the operation modes related to air conditioning in the vehicle cabin include a cooling mode, a heating mode, and a dehumidifying and heating mode.

[0107] Furthermore, since the automotive air conditioner 1 can adjust the temperature of the battery 31 mounted on the vehicle, it includes a battery cooling mode and an air conditioning cooling mode as operating modes for cooling the battery 31. When automatic control operation is enabled, switching between these operating modes is performed by executing a control program stored in advance in the control device 50.

[0108] More specifically, the control program calculates the target outlet temperature TAO of the air to be blown into the vehicle cabin based on the detection signals detected by the group of air conditioning control sensors and the operation signals output from the operation panel 51.

[0109] Specifically, the target air outlet temperature TAO is calculated by the following formula F1: TAO=Kset×Tset−Kr×Tr−Kam×Tam−Ks×As+C (F1), where Tset is the target temperature inside the vehicle cabin set by the temperature setting switch (vehicle cabin set temperature), Tr is the inside air temperature detected by the inside air temperature sensor 52a, Tam is the outside air temperature detected by the outside air temperature sensor 52b, and As is the amount of solar radiation detected by the solar radiation sensor 52c. Kset, Kr, Kam, and Ks are control gains, and C is a correction constant.

[0110] In the control program, when the air conditioner switch on the operation panel 51 is turned on, the rotation speed of the compressor 11, the throttle opening of the first expansion valve 15a and the second expansion valve 15b, the air flow rate of the blower 42, etc. are controlled according to the target blowing temperature TAO.

[0111] The operating modes of the automotive air conditioner 1 will be described below. First, the cooling mode of the automotive air conditioner 1 will be described with reference to Fig. 4. The cooling mode is an operating mode in which the interior evaporator 16 cools the blown air W and blows it into the vehicle cabin without cooling the battery 31. In the cooling mode, the interior evaporator 16, which corresponds to the first evaporator, cools the blown air W, which is the first object to be cooled, and therefore this mode is an example of a cooling mode. In this cooling mode, the control device 50 opens the first expansion valve 15a by a predetermined throttle opening and fully closes the second expansion valve 15b.

[0112] Therefore, in the refrigeration cycle 10 in the cooling mode, a refrigerant circulation circuit is formed in which the refrigerant flows in the following order: the compressor 11, the heat medium refrigerant heat exchanger 12, the branching section 13, the subcooler 14, the first expansion valve 15a, the indoor evaporator 16, the evaporation pressure control valve 18, the junction section 19, and the compressor 11. That is, in the cooling mode, the refrigerant circuit is switched to one in which the blown air W blown by the blower 42 is cooled by the indoor evaporator 16.

[0113] In this cycle configuration, the control device 50 controls the operation of various control target devices connected to the output side. For example, the control device 50 controls the operation of the compressor 11 so that the refrigerant evaporation temperature Tefin detected by the evaporator temperature sensor 52e becomes the target evaporation temperature TEO. The target evaporation temperature TEO is determined based on the target outlet temperature TAO by referring to a control map for the cooling mode stored in the control device 50 in advance.

[0114] Specifically, in this control map, the target evaporation temperature TEO is increased as the target outlet temperature TAO increases so that the outlet air temperature TAV detected by the outlet air temperature sensor 52f approaches the target outlet temperature TAO. Furthermore, the target evaporation temperature TEO is determined to be within a range (specifically, 1°C or higher) that can suppress frost formation on the interior evaporator 16.

[0115] Based on the target blowing temperature TAO, the control device 50 determines the control voltage (blowing capacity) of the blower 42 by referring to a control map previously stored in the control device 50. Specifically, in this control map, the airflow rate of the blower 42 is maximized in the extremely low temperature range (maximum cooling range) and the extremely high temperature range (maximum heating range) of the target blowing temperature TAO, and the airflow rate is reduced as the temperature approaches the intermediate temperature range.

[0116] For the heating unit 20 in the cooling mode, the control device 50 controls the operation of the high-temperature side pump 26 so as to exert a predetermined water pumping capacity for the cooling mode. The control device 50 also controls the high-temperature side flow adjustment valve 25 so as to connect the inlet / outlet on the radiator 22 side with the inlet / outlet on the electric heater 24 side, and to close the inlet / outlet on the heater core 23 side.

[0117] As a result, in the high-temperature side heat medium circuit 21 in the cooling mode, a circulation circuit for the high-temperature side heat medium is formed, which circulates through the high-temperature side pump 26, the heat medium refrigerant heat exchanger 12, the electric heater 24, the high-temperature side flow control valve 25, the radiator 22, and the high-temperature side pump 26 in that order.

[0118] Furthermore, for the low-temperature side heat medium circuit 30 in the cooling mode, the control device 50 keeps the components of the low-temperature side heat medium circuit 30 in a stopped state without operating them.

[0119] As described above, in the refrigeration cycle 10 in the cooling mode, the high-pressure refrigerant discharged from the compressor 11 flows into the heat medium refrigerant heat exchanger 12. In the heat medium refrigerant heat exchanger 12, since the high-temperature side pump 26 is operating, the high-pressure refrigerant and the high-temperature side heat medium of the high-temperature side heat medium circuit 21 exchange heat, whereby the high-pressure refrigerant is cooled and condensed, and the high-temperature side heat medium is heated.

[0120] In the high-temperature side heat medium circuit 21, the high-temperature side heat medium heated in the heat medium-refrigerant heat exchanger 12 flows into the radiator 22 via the electric heater 24 and the high-temperature side flow control valve 25. The high-temperature side heat medium that has flowed into the radiator 22 exchanges heat with the outside air OA and dissipates heat. The high-temperature side heat medium that has been cooled in the radiator 22 is sucked into the high-temperature side pump 26 and is pumped back into the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12.

[0121] Meanwhile, the high-pressure refrigerant that has passed through the refrigerant passage 12a of the heat medium refrigerant heat exchanger 12 flows into the sub-cooler 14 via the branching portion 13. While flowing through the sub-cooler 14, the refrigerant dissipates heat to the outside air, which is a heat dissipation target, and is thereby supercooled.

[0122] The refrigerant flowing out of the subcooler 14 flows into the first expansion valve 15a and is decompressed. The throttle opening of the first expansion valve 15a is adjusted so that the degree of superheat of the refrigerant on the outlet side of the indoor evaporator 16 is approximately 3°C.

[0123] The low-pressure refrigerant decompressed by the first expansion valve 15a flows into the indoor evaporator 16. The refrigerant that has flowed into the indoor evaporator 16 absorbs heat from the blown air W sent from the blower 42 and evaporates, cooling the blown air W. The refrigerant that has flowed out of the indoor evaporator 16 passes through the evaporation pressure control valve 18 and the junction 19 and is drawn into the compressor 11, where it is compressed again.

[0124] Therefore, in the cooling mode, the vehicle air conditioner 1 can cool the vehicle interior by blowing the blown air W cooled by the interior evaporator 16 into the vehicle interior. At this time, the degree of subcooling of the refrigerant can be increased in the subcooler 14, so the vehicle air conditioner 1 can increase the cooling capacity of the refrigeration cycle 10.

[0125] In this cooling mode, the high-temperature side heat medium circuit 21 is configured to radiate heat from the high-temperature side heat medium to the outside air OA, so the electric heater 24 is not operated. Needless to say, the electric heater 24 may be operated as needed.

[0126] Next, the heating mode of the vehicle air conditioner 1 will be described with reference to Fig. 5. The heating mode is an operation mode in which the outside air OA is used as a heat source to heat the blown air W by the heater core 23 and blow the heated air into the vehicle cabin. In the heating mode, the blown air W, which is the object to be heated, is heated by the heating unit 20 including the heat medium refrigerant heat exchanger 12 and the heater core 23, and therefore corresponds to an example of the heating mode according to the present embodiment.

[0127] When air conditioning operation is performed in the heating mode, it is assumed that the outside air temperature is low. In this case, if the refrigeration cycle 10 is configured to circulate the refrigerant through the sub-cooler 14, the compression power of the compressor 11 in the refrigeration cycle 10 may increase due to the influence of heat exchange between the sub-cooler 14 and the low-temperature outside air.

[0128] In consideration of this, in the heating mode according to the present embodiment, the control device 50 opens the second expansion valve 15b by a predetermined throttle opening and fully closes the first expansion valve 15a. Therefore, in the refrigeration cycle 10 in the heating mode, a heat pump cycle is configured in which the refrigerant circulates in the following order: the compressor 11, the heat medium-refrigerant heat exchanger 12, the branching unit 13, the second expansion valve 15b, the chiller 17, the junction unit 19, and the compressor 11. In other words, in the heating mode, the refrigerant is caused to flow into the chiller 17 without passing through the subcooler 14, and heat absorbed from the low-temperature side heat medium in the low-temperature side heat medium circuit 30 is pumped up and switched to a refrigerant circuit that can be used to heat the blown air W.

[0129] In this cycle configuration, the control device 50 controls the operation of various control target devices connected to the output side. For example, the control device 50 controls the operation of the compressor 11 so that the high-pressure refrigerant pressure Pd detected by the high-pressure sensor 52d becomes the target high-pressure PCO.

[0130] The target high pressure PCO is determined based on the target outlet temperature TAO by referring to a control map for the heating mode pre-stored in the control device 50. Specifically, in this control map, the target high pressure PCO is increased as the target outlet temperature TAO increases so that the blown air temperature TAV approaches the target outlet temperature TAO.

[0131] Similarly to the cooling mode, the control device 50 determines the control voltage (blowing capacity) of the blower 42. The control device 50 controls the operation of the air mix door 44 so that the ventilation passage on the heater core 23 side is fully opened and the cool air bypass passage 45 is closed.

[0132] For the heating unit 20 in the heating mode, the control device 50 operates the high-temperature side pump 26 to exert a predetermined water pumping capacity for the heating mode. The control device 50 also controls the high-temperature side flow adjustment valve 25 to connect the inlet / outlet on the heater core 23 side with the inlet / outlet on the electric heater 24 side, and to close the inlet / outlet on the radiator 22 side.

[0133] As a result, in the high-temperature side heat medium circuit 21 in heating mode, a circulation circuit of the high-temperature side heat medium is formed, which circulates in the following order: high-temperature side pump 26, heat medium refrigerant heat exchanger 12, electric heater 24, high-temperature side flow control valve 25, heater core 23, and high-temperature side pump 26.

[0134] In addition, for the low-temperature side heat medium circuit 30 in the heating mode, the control device 50 controls the operation of the low-temperature side pump 34 so as to demonstrate the water pumping capacity in the heating mode. The control device 50 also controls the operation of the low-temperature side flow rate adjustment valve 33 so as to communicate the inlet / outlet on the chiller 17 side with the inlet / outlet on the outside-air heat exchanger 32 side and close the inlet / outlet on the battery 31 side.

[0135] As a result, in the low-temperature side heat medium circuit 30 in heating mode, a circulation circuit for the low-temperature side heat medium is formed in which the low-temperature side heat medium circulates in the following order: low-temperature side pump 34, outdoor air heat exchanger 32, low-temperature side flow rate adjustment valve 33, chiller 17, and low-temperature side pump 34.

[0136] Here, the low-temperature side heat medium in the low-temperature side heat medium circuit 30 is cooled by the chiller 17, and therefore absorbs heat from the outside air OA when passing through the outside air heat exchanger 32. That is, in the heating mode, the vehicle air conditioner 1 can use the heat of the outside air OA as a heat source for heating.

[0137] In the heating mode of the refrigeration cycle 10, the high-pressure refrigerant flowing out of the refrigerant passage 12a of the heat medium-refrigerant heat exchanger 12 flows into the second expansion valve 15b and is reduced in pressure without passing through the sub-cooler 14. The throttle opening of the second expansion valve 15b is adjusted so that the refrigerant at the outlet side of the chiller 17 is in a gas-liquid two-phase state. The low-pressure refrigerant evaporates by exchanging heat with the low-temperature side heat medium in the chiller 17, and can absorb heat from the low-temperature side heat medium.

[0138] The refrigerant that has absorbed heat from the low-temperature side heat medium is compressed by the compressor 11 and discharged as high-pressure refrigerant to the heat medium-refrigerant heat exchanger 12. Because the high-temperature side pump 26 is operating, in the heat medium-refrigerant heat exchanger 12, the high-pressure refrigerant exchanges heat with the high-temperature side heat medium of the high-temperature side heat medium circuit 21, and the high-pressure refrigerant is cooled and condensed. As a result, the high-temperature side heat medium is heated by the heat of the high-pressure refrigerant.

[0139] In the high-temperature side heat medium circuit 21, the high-temperature side heat medium heated in the heat medium-refrigerant heat exchanger 12 flows into the heater core 23 via the high-temperature side flow control valve 25. Since the air mix door 44 fully opens the ventilation passage on the heater core 23 side, the high-temperature side heat medium that has flowed into the heater core 23 exchanges heat with the blown air W that has passed through the indoor evaporator 16 and dissipates heat.

[0140] As a result, in the heating mode, the blown air W is heated, and the temperature of the blown air W approaches the target blown temperature TAO. The high-temperature side heat medium flowing out of the heater core 23 is sucked into the high-temperature side pump 26 and is pumped again to the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12.

[0141] That is, the vehicle air conditioning device 1 in heating mode can pump up heat absorbed from the outside air OA in the low-temperature side heat medium circuit 30 using the refrigeration cycle 10 and use it to heat the blown air W via the high-temperature side heat medium circuit 21.

[0142] Furthermore, in the heating mode of the vehicle air conditioner 1, the refrigeration cycle 10 has a circuit configuration in which the refrigerant circulates without passing through the sub-cooler 14, thereby suppressing the influence of low-temperature outside air OA in the sub-cooler 14. Since the refrigerant is not cooled too much by the influence of low-temperature outside air OA, the refrigeration cycle 10 in the heating mode can suppress an increase in the compression power of the compressor 11, and can realize heating of the object to be heated with appropriate compression power.

[0143] Next, the dehumidifying and heating mode of the vehicle air conditioner 1 will be described with reference to Fig. 6. The dehumidifying and heating mode is an operation mode in which the blown air W cooled by the interior evaporator 16 is heated by the heater core 23 and blown into the vehicle cabin. In the dehumidifying and heating mode, the control device 50 opens the first expansion valve 15a and the second expansion valve 15b to predetermined throttle openings.

[0144] Therefore, in the refrigeration cycle 10 in the dehumidifying and heating mode, the refrigerant flow branches into two at the branching portion 13 and merges into one at the junction 19. In the dehumidifying and heating mode, one refrigerant flow circulates through the compressor 11, the heat medium refrigerant heat exchanger 12, the branching portion 13, the subcooler 14, the first expansion valve 15a, the indoor evaporator 16, the evaporation pressure control valve 18, the junction 19, and the compressor 11 in that order. At the same time, the refrigerant circulates through the compressor 11, the heat medium refrigerant heat exchanger 12, the branching portion 13, the second expansion valve 15b, the chiller 17, the junction 19, and the compressor 11 in that order.

[0145] That is, in the refrigeration cycle 10 in the dehumidifying and heating mode, a heat pump cycle is configured in which the indoor evaporator 16 and the chiller 17 are connected in parallel to the flow of refrigerant flowing out from the heat medium refrigerant heat exchanger 12. In the dehumidifying and heating mode, refrigerant is allowed to flow into the sub-cooler 14 and the indoor evaporator 16, and refrigerant is also allowed to flow into the chiller 17, which corresponds to an example of the parallel mode in this embodiment.

[0146] In this cycle configuration, the control device 50 controls the operation of various control target devices connected to the output side. For example, similar to the heating mode, the control device 50 controls the operation of the compressor 11 so that the high-pressure refrigerant pressure Pd becomes the target high-pressure PCO.

[0147] For the heating unit 20 in the dehumidifying and heating mode, the control device 50 operates the high-temperature side pump 26 to achieve a predetermined water pumping capacity for the dehumidifying and heating mode. The control device 50 also controls the high-temperature side flow control valve 25 to connect the inlet / outlet on the heater core 23 side with the inlet / outlet on the electric heater 24 side, and to close the inlet / outlet on the radiator 22 side.

[0148] As a result, in the high-temperature side heat medium circuit 21 in the dehumidifying heating mode, a circulation circuit for the high-temperature side heat medium is formed, which circulates in the following order: high-temperature side pump 26, heat medium-refrigerant heat exchanger 12, electric heater 24, high-temperature side flow control valve 25, heater core 23, and high-temperature side pump 26.

[0149] Furthermore, for the low-temperature side heat medium circuit 30 in the dehumidifying heating mode, the control device 50 controls the operation of the low-temperature side pump 34 so as to demonstrate the water pumping capacity in the dehumidifying heating mode. The control device 50 also controls the operation of the low-temperature side flow rate adjustment valve 33 so as to communicate the inlet / outlet on the chiller 17 side with the inlet / outlet on the outside-air heat exchanger 32 side and close the inlet / outlet on the battery 31 side.

[0150] As a result, in the low-temperature side heat medium circuit 30 in the dehumidifying heating mode, a circulation circuit for the low-temperature side heat medium is formed, which circulates in the following order: low-temperature side pump 34, outdoor air heat exchanger 32, low-temperature side flow control valve 33, chiller 17, and low-temperature side pump 34.

[0151] In the dehumidifying and heating mode of the refrigeration cycle 10, the high-pressure refrigerant flowing out of the refrigerant passage 12a of the heat medium refrigerant heat exchanger 12 is branched at the branching portion 13. One of the high-pressure refrigerants branched at the branching portion 13 flows into the subcooler 14 and exchanges heat with outside air. The refrigerant supercooled by heat radiation from the outside air in the subcooler 14 flows into the first expansion valve 15a and is decompressed. The low-pressure refrigerant decompressed by the first expansion valve 15a flows into the indoor evaporator 16.

[0152] The refrigerant that flows into the interior evaporator 16 absorbs heat from the blown air W blown by the blower 42 and evaporates, cooling the blown air W. The refrigerant that flows out of the interior evaporator 16 passes through the evaporation pressure control valve 18 and the junction 19 and is drawn into the compressor 11, where it is compressed again.

[0153] Meanwhile, the other of the high-pressure refrigerants branched at the refrigerant branching section flows into the second expansion valve 15b and is decompressed without passing through the sub-cooler 14. The low-pressure refrigerant decompressed by the second expansion valve 15b flows into the chiller 17 and exchanges heat with the low-temperature side heat medium flowing through the heat medium passage 17b. Therefore, the low-pressure refrigerant evaporates by exchanging heat with the low-temperature side heat medium and can absorb heat from the low-temperature side heat medium. The refrigerant that has absorbed heat from the low-temperature side heat medium is drawn into the compressor 11 and compressed again.

[0154] The high-pressure refrigerant discharged from the compressor 11 condenses in the heat medium-refrigerant heat exchanger 12 by exchanging heat with the high-temperature side heat medium of the high-temperature side heat medium circuit 21. As a result, the high-temperature side heat medium is heated using the heat of the high-pressure refrigerant as a heat source.

[0155] In the high-temperature side heat medium circuit 21, the high-temperature side heat medium heated in the heat medium-refrigerant heat exchanger 12 flows into the heater core 23 via the high-temperature side flow control valve 25. The high-temperature side heat medium that has flowed into the heater core 23 exchanges heat with the blown air W cooled in the indoor evaporator 16 and dissipates heat.

[0156] In the dehumidifying and heating mode, the blown air W cooled by the interior evaporator 16 can be heated, thereby realizing dehumidifying and heating of the vehicle interior. The high-temperature side heat medium flowing out of the heater core 23 is sucked into the high-temperature side pump 26 and is pumped again to the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12.

[0157] That is, the vehicle air conditioning device 1 in the dehumidifying heating mode can pump up the exhaust heat absorbed from the battery 31 in the low-temperature side heat medium circuit 30 in the refrigeration cycle 10 and use it as a heat source to heat the cooled blown air W via the high-temperature side heat medium circuit 21.

[0158] When operating in the dehumidifying heating mode, it is assumed that the outdoor temperature is higher than in the heating mode. Therefore, even if a circuit configuration in which part of the high-pressure refrigerant circulates through the sub-cooler 14 is adopted in the dehumidifying heating mode, the refrigerant will not be cooled too much by the influence of the outdoor temperature, and the influence on the compression power of the compressor 11 can be suppressed. Furthermore, since a circuit configuration in which part of the high-pressure refrigerant circulates through the sub-cooler 14 is adopted in the dehumidifying heating mode, the dehumidification performance of the blown air W can be improved.

[0159] Next, the details of the control for selecting the air conditioning operation mode in the vehicle air conditioner 1 according to this embodiment will be described with reference to Fig. 7. The vehicle air conditioner 1 is configured to switch between the cooling mode, the dehumidifying and heating mode, and the heating mode depending on the temperature of the outside air OA (i.e., the outside air temperature Tam), which corresponds to the heat dissipation target in the subcooler 14.

[0160] Fig. 7 shows the control content related to the selection of the operation mode when the automatic control operation is enabled in the automotive air conditioner 1. The control program according to Fig. 7 is executed by the control device 50 when the automatic control operation is enabled in the automotive air conditioner 1.

[0161] In step S1, it is determined whether the outside air temperature Tam detected by the outside air temperature sensor 52b is lower than a predetermined first reference temperature KTaml. The first reference temperature KTaml is set to, for example, 0°C, in consideration of the fact that the refrigerant may become too cold due to heat exchange between the outside air and the refrigerant in the subcooler 14.

[0162] If the outside air temperature Tam detected by the outside air temperature sensor 52b is lower than the first reference temperature KTaml, the process proceeds to step S2. On the other hand, if the outside air temperature Tam is equal to or higher than the first reference temperature KTaml, the process proceeds to step S3.

[0163] In step S2, the operation mode of the automotive air conditioner 1 is set to the heating mode. After the operation mode of the automotive air conditioner 1 is set to the heating mode, the control program shown in Fig. 7 is terminated. Note that the control program shown in Fig. 7 is repeatedly executed as long as the automatic control operation is enabled in the automotive air conditioner 1.

[0164] As described above, when the outside air temperature Tam is low, if the subcooler 14 is used to exchange heat between the refrigerant and the outside air OA to supercool the refrigerant, the refrigerant may become too cold, resulting in an increase in the compression power of the refrigeration cycle 10. In this regard, in the heating mode of this embodiment, as shown in Fig. 5, the refrigerant is switched to a circuit in which the refrigerant circulates through the refrigeration cycle 10 without passing through the subcooler 14. Therefore, the vehicle air conditioner 1 can heat the vehicle cabin using appropriate compression power even in an environment where the outside air temperature Tam is low.

[0165] In step S3, it is determined whether the outside air temperature Tam detected by the outside air temperature sensor 52b is lower than a predetermined second reference temperature KTamh. The second reference temperature KTamh indicates an outside air temperature higher than the first reference temperature KTaml, and is set to, for example, 30°C. If the outside air temperature Tam is lower than the second reference temperature KTamh, the process proceeds to step S4. If the outside air temperature Tam is equal to or higher than the second reference temperature KTamh, the process proceeds to step S5.

[0166] In step S4, the operation mode of the automotive air conditioner 1 is set to the dehumidifying heating mode. After the operation mode of the automotive air conditioner 1 is set to the dehumidifying heating mode, the control program shown in Fig. 7 is terminated. Note that the control program shown in Fig. 7 is repeatedly executed as long as the automatic control operation is enabled in the automotive air conditioner 1.

[0167] In this way, in the vehicle air conditioning system 1, when the outside air temperature Tam is within the range from the first reference temperature KTaml to the second reference temperature KTamh, the dehumidifying and heating mode shown in Figure 6 is executed, thereby achieving comfortable air conditioning in the vehicle cabin according to the outside air temperature Tm.

[0168] In step S5, the operation mode of the automotive air conditioner 1 is set to the cooling mode. After the operation mode of the automotive air conditioner 1 is set to the cooling mode, the control program shown in Fig. 7 is terminated. Note that the control program shown in Fig. 7 is repeatedly executed as long as the automatic control operation is enabled in the automotive air conditioner 1.

[0169] In this way, when the outside air temperature Tam is equal to or higher than the second reference temperature KTamh, the vehicle air conditioner 1 operates in the cooling mode shown in Fig. 4. As described above, in the cooling mode according to this embodiment, the refrigerant in the refrigeration cycle 10 flows out of the heat medium refrigerant heat exchanger 12 and then circulates by flowing through the subcooler 14. When the refrigerant flows through the subcooler 14, the degree of subcooling of the refrigerant increases due to heat exchange with the outside air OA, thereby improving the cooling capacity of the refrigeration cycle 10 in the cooling mode.

[0170] 7, the vehicle air conditioner 1 according to this embodiment can switch between the cooling mode, the heating mode, and the dehumidifying and heating mode depending on the outside air temperature Tam detected by the outside air temperature sensor 52b. That is, the vehicle air conditioner 1 can improve the comfort of the vehicle interior with appropriate air conditioning performance depending on the environment including the outside air temperature Tam.

[0171] As described above, the vehicle air conditioner 1 according to this embodiment can adjust the temperature of on-board equipment such as the battery 31 in addition to air conditioning the interior of the vehicle using the refrigeration cycle 10. Here, the battery cooling mode and the air conditioning cooling mode, which are included in the operation modes including the temperature adjustment of the on-board equipment, will be described with reference to FIGS.

[0172] First, the battery cooling mode of the vehicle air conditioner 1 will be described with reference to Fig. 8. The battery cooling mode is an operation mode that cools the battery 31 without performing air conditioning operation in the vehicle cabin. The battery cooling mode is executed when a battery cooling command is received while the automatic control operation of the vehicle air conditioner 1 is not enabled and air conditioning operation in the vehicle cabin is not being performed.

[0173] Here, the battery cooling command is output to the control device 50 when, for example, a vehicle ECU mounted on the vehicle determines that cooling of the battery 31 is necessary. When the battery temperature TBA detected by the battery temperature sensor 52g exceeds a predetermined reference value, the vehicle ECU outputs the battery cooling command to the control device 50.

[0174] In the battery cooling mode according to the present embodiment, the control device 50 opens the second expansion valve 15b by a predetermined throttle opening and fully closes the first expansion valve 15a. Therefore, in the refrigeration cycle 10 in the battery cooling mode, as in the heating mode, a heat pump cycle is configured in which the refrigerant circulates through the compressor 11, the heat medium refrigerant heat exchanger 12, the branching section 13, the second expansion valve 15b, the chiller 17, the junction section 19, and the compressor 11 in this order.

[0175] In this cycle configuration, the control device 50 controls the operation of various controlled devices connected to the output side. For example, the control device 50 controls the refrigerant discharge capacity of the compressor 11 and the opening degree of the second expansion valve 15b so as to be suitable for the battery cooling mode. Note that in the electric cooling mode, there is no need to perform cabin air conditioning, so detailed control of the components of the interior air conditioning unit 40 is not performed.

[0176] For the heating unit 20 in the battery cooling mode, the control device 50 operates the high-temperature side pump 26 to achieve a predetermined water pumping capacity for the battery cooling mode. The control device 50 also controls the high-temperature side flow adjustment valve 25 to connect the inlet / outlet on the radiator 22 side with the inlet / outlet on the electric heater 24 side, and to close the inlet / outlet on the heater core 23 side.

[0177] As a result, in the high-temperature side heat medium circuit 21 in the battery cooling mode, a circulation circuit for the high-temperature side heat medium is formed, in which the high-temperature side heat medium circulates in the following order: high-temperature side pump 26, heat medium-refrigerant heat exchanger 12, electric heater 24, high-temperature side flow control valve 25, radiator 22, and high-temperature side pump 26. When flowing through the radiator 22, heat of the high-temperature side heat medium is dissipated to the outside air.

[0178] Furthermore, for the low-temperature side heat medium circuit 30 in the battery cooling mode, the control device 50 controls the operation of the low-temperature side pump 34 so as to demonstrate the water pumping capacity in the battery cooling mode. The control device 50 also controls the operation of the low-temperature side flow rate adjustment valve 33 so as to connect the inlet / outlet on the chiller 17 side with the inlet / outlet on the battery 31 side and close the inlet / outlet on the outside-air heat exchanger 32 side.

[0179] As a result, in the low-temperature side heat medium circuit 30 in the battery cooling mode, a circulation circuit for the low-temperature side heat medium is formed, in which the low-temperature side heat medium circulates in the following order: low-temperature side pump 34, battery 31, low-temperature side flow rate adjustment valve 33, chiller 17, and low-temperature side pump 34. Here, since the low-temperature side heat medium in the low-temperature side heat medium circuit 30 has been cooled by the chiller 17, it absorbs heat generated in the battery 31 when passing through the heat medium passage of the battery 31.

[0180] In the refrigeration cycle 10 in the battery cooling mode, the high-pressure refrigerant flowing out of the refrigerant passage 12a of the heat medium-refrigerant heat exchanger 12 flows into the second expansion valve 15b and is reduced in pressure without passing through the sub-cooler 14. The throttle opening of the second expansion valve 15b is adjusted so that the refrigerant at the outlet side of the chiller 17 is in a gas-liquid two-phase state. The low-pressure refrigerant evaporates by exchanging heat with the low-temperature heat medium in the chiller 17, and can absorb heat from the low-temperature heat medium.

[0181] The refrigerant that has absorbed heat from the low-temperature side heat medium is compressed by the compressor 11 and discharged as high-pressure refrigerant to the heat medium-refrigerant heat exchanger 12. Because the high-temperature side pump 26 is operating, in the heat medium-refrigerant heat exchanger 12, the high-pressure refrigerant exchanges heat with the high-temperature side heat medium of the high-temperature side heat medium circuit 21, and the high-pressure refrigerant is cooled and condensed. As a result, the high-temperature side heat medium is heated by the heat of the high-pressure refrigerant.

[0182] In the high-temperature side heat medium circuit 21, the high-temperature side heat medium heated in the heat medium-refrigerant heat exchanger 12 flows into the radiator 22 via the high-temperature side flow control valve 25. The high-temperature side heat medium that has flowed into the radiator 22 exchanges heat with the outside air OA and dissipates heat.

[0183] As a result, in the battery cooling mode, the heat absorbed from the battery 31 in the low-temperature side heat medium circuit 30 is pumped up by the refrigeration cycle 10 and dissipated into the outside air OA via the high-temperature side heat medium circuit 21, thereby cooling the battery 31.

[0184] Next, the air conditioning cooling mode of the vehicle air conditioner 1 will be described with reference to Fig. 9. The air conditioning cooling mode is an operating mode in which the air conditioning is performed to cool the vehicle interior and the battery 31. The air conditioning cooling mode is entered when a battery cooling command is received while the air conditioning mode is being performed.

[0185] In the cooling / cooling mode according to this embodiment, the control device 50 opens the first expansion valve 15 a and the second expansion valve 15 b to predetermined openings. Therefore, in the refrigeration cycle 10 in the cooling / cooling mode, the refrigerant flow branches into two at the branching portion 13 and merges into one at the merging portion 19, similar to the dehumidifying heating mode.

[0186] In the air-conditioning cooling mode, one refrigerant flows and circulates in the order of the compressor 11, the heat medium refrigerant heat exchanger 12, the branching section 13, the sub-cooler 14, the first expansion valve 15a, the indoor evaporator 16, the evaporation pressure control valve 18, the junction section 19, and the compressor 11. At the same time, the refrigerant circulates in the order of the compressor 11, the heat medium refrigerant heat exchanger 12, the branching section 13, the second expansion valve 15b, the chiller 17, the junction section 19, and the compressor 11.

[0187] That is, in the refrigeration cycle 10 in the cooling / cooling mode, a heat pump cycle is configured in which the indoor evaporator 16 and the chiller 17 are connected in parallel to the flow of refrigerant flowing out from the heat medium refrigerant heat exchanger 12 .

[0188] In this cycle configuration, the control device 50 controls the operation of various controlled devices connected to the output side. For example, the control device 50 controls the refrigerant discharge capacity of the compressor 11, the opening degree of the first expansion valve 15a, and the opening degree of the second expansion valve 15b so as to be suitable for the cooling / cooling mode. In the cooling / cooling mode, it is necessary to cool the vehicle cabin, so each component of the interior air conditioning unit 40 is controlled in the same way as in the cooling mode.

[0189] For the heating unit 20 in the air conditioning / cooling mode, the control device 50 operates the high-temperature side pump 26 to achieve a predetermined water pumping capacity for the air conditioning / cooling mode. The control device 50 also controls the high-temperature side flow adjustment valve 25 to connect the inlet / outlet on the radiator 22 side with the inlet / outlet on the electric heater 24 side, and to close the inlet / outlet on the heater core 23 side.

[0190] As a result, in the high-temperature side heat medium circuit 21 in the air conditioning / cooling mode, a circulation circuit for the high-temperature side heat medium is formed, which circulates in the following order: high-temperature side pump 26, heat medium refrigerant heat exchanger 12, electric heater 24, high-temperature side flow control valve 25, radiator 22, and high-temperature side pump 26.

[0191] In addition, for the low-temperature side heat medium circuit 30 in the air-conditioning cooling mode, the control device 50 controls the operation of the low-temperature side pump 34 so as to demonstrate the water pressure-feeding capacity in the dehumidifying heating mode. The control device 50 also controls the operation of the low-temperature side flow rate adjustment valve 33 so as to connect the inlet / outlet on the chiller 17 side with the inlet / outlet on the battery 31 side and close the inlet / outlet on the outside-air heat exchanger 32 side.

[0192] As a result, in the low-temperature side heat medium circuit 30 in the air-conditioning cooling mode, a circulation circuit for the low-temperature side heat medium is formed in which the low-temperature side pump 34, battery 31, low-temperature side flow rate adjustment valve 33, chiller 17, and low-temperature side pump 34 are circulated in this order.

[0193] In the refrigeration cycle 10 in the air-conditioning mode, the high-pressure refrigerant flowing out of the refrigerant passage 12a of the heat medium refrigerant heat exchanger 12 is branched at the branching portion 13. One of the high-pressure refrigerants branched at the branching portion 13 flows into the sub-cooler 14 and exchanges heat with outside air. The refrigerant supercooled by heat radiation from the outside air in the sub-cooler 14 flows into the first expansion valve 15a and is decompressed. The low-pressure refrigerant decompressed by the first expansion valve 15a flows into the indoor evaporator 16.

[0194] The refrigerant that flows into the interior evaporator 16 absorbs heat from the blown air W blown by the blower 42 and evaporates, cooling the blown air W. The refrigerant that flows out of the interior evaporator 16 passes through the evaporation pressure control valve 18 and the junction 19 and is drawn into the compressor 11, where it is compressed again.

[0195] Meanwhile, the other of the high-pressure refrigerants branched at the refrigerant branching section flows into the second expansion valve 15b and is decompressed without passing through the sub-cooler 14. The low-pressure refrigerant decompressed by the second expansion valve 15b flows into the chiller 17 and exchanges heat with the low-temperature side heat medium flowing through the heat medium passage 17b. Therefore, the low-pressure refrigerant evaporates by exchanging heat with the low-temperature side heat medium and can absorb heat from the low-temperature side heat medium. The refrigerant that has absorbed heat from the low-temperature side heat medium is drawn into the compressor 11 and compressed again.

[0196] The high-pressure refrigerant discharged from the compressor 11 condenses in the heat medium-refrigerant heat exchanger 12 by exchanging heat with the high-temperature side heat medium of the high-temperature side heat medium circuit 21. As a result, the high-temperature side heat medium is heated using the heat of the high-pressure refrigerant as a heat source.

[0197] In the high-temperature side heat medium circuit 21, the high-temperature side heat medium heated in the heat medium-refrigerant heat exchanger 12 flows into the radiator 22 via the high-temperature side flow control valve 25. The high-temperature side heat medium that has flowed into the radiator 22 exchanges heat with the outside air OA and dissipates heat.

[0198] As a result, in the air conditioning / cooling mode, the blown air W is cooled by the interior evaporator 16, and the battery 31 is cooled via the chiller 17 and the low-temperature side heat medium circuit 30. That is, by executing the air conditioning / cooling mode, the vehicle air conditioner 1 can ensure comfort in the vehicle cabin by cooling, and at the same time, can appropriately adjust the temperature of the battery 31. Here, in the air conditioning / cooling mode, refrigerant is allowed to flow into the chiller 17, and heat is dissipated to the outside air OA by the radiator 22, so this mode corresponds to an example of a heat dissipation cooling mode in this embodiment.

[0199] The operating modes described in this embodiment are merely examples, and various changes can be made to the circulation path of the high-temperature side heat medium in the high-temperature side heat medium circuit 21 and the circulation path of the low-temperature side heat medium in the low-temperature side heat medium circuit 30, for example.

[0200] For example, in the above-described explanation of each operation mode, the high-temperature side heat medium that has flowed through the heat medium-refrigerant heat exchanger 12 in the high-temperature side heat medium circuit 21 has been described as circulating by flowing through either the radiator 22 or the heater core 23. However, the present invention is not limited to this. That is, for the flow of the high-temperature side heat medium that has flowed through the heat medium-refrigerant heat exchanger 12, a heat medium circulation path that connects the radiator 22 and the heater core 23 in parallel may be adopted.

[0201] At this time, the operation of the high-temperature side flow control valve 25 can be controlled to adjust the flow rate ratio of the high-temperature side heat medium flowing through the radiator 22 side and the heater core 23 side. This allows the vehicle air conditioning device 1 to adjust the balance between the amount of heat used to heat the blown air W in the heater core 23 and the amount of heat radiated to the outside air by the radiator 22, and adjust the amount of heat possessed by the high-temperature side heat medium to a desired state.

[0202] Similarly, in the above-described explanations of the respective operation modes, the low-temperature side heat medium flowing out from the chiller 17 of the low-temperature side heat medium circuit 30 is described as circulating by flowing through either the heat medium passage of the battery 31 or the outside-air heat exchanger 32, but this is not limited to this. That is, with regard to the flow of the low-temperature side heat medium circulating through the chiller 17, a circulation path may be adopted in which the heat medium passage of the battery 31 and the outside-air heat exchanger 32 are connected in parallel.

[0203] At this time, by controlling the operation of the low-temperature side flow control valve 33 and adjusting the flow rate ratio of the low-temperature side heat medium flowing through the heat medium passage side of the battery 31 and the outside air heat exchanger 32 side, the balance of the heat absorbed on the low-pressure side of the refrigeration cycle 10 can be adjusted between the exhaust heat of the battery 31 and the outside air.

[0204] As described above, according to the vehicle air conditioning system 1 of this embodiment, when the system is operated in the cooling mode, as shown in Fig. 4, the inflow of refrigerant into the chiller 17 is blocked. Therefore, the refrigerant circulates by flowing through the compressor 11, the heat medium refrigerant heat exchanger 12, the branching section 13, the subcooler 14, the first expansion valve 15a, the interior evaporator 16, the junction section 19, and the compressor 11 in this order.

[0205] Therefore, in the vehicle air conditioner 1 in the cooling mode, the degree of subcooling of the refrigerant can be increased by dissipating heat to the outside air OA in the subcooler 14, thereby improving the cooling capacity. That is, the vehicle air conditioner 1 according to this embodiment can achieve cooling operation in the vehicle cabin using a high cooling capacity.

[0206] 5, in the vehicle air conditioner 1 in the heating mode, the refrigerant is blocked from flowing into the sub-cooler 14. That is, in the heating mode, the refrigerant circulates by flowing through the compressor 11, the heat medium refrigerant heat exchanger 12, the branching unit 13, the second expansion valve 15b, the chiller 17, the junction unit 19, and the compressor 11 in this order.

[0207] In the refrigeration cycle 10, when the refrigerant is circulated through the subcooler 14, heat exchange occurs between the refrigerant and the outside air OA in the subcooler 14. For example, if the outside air OA is at a low temperature, it is expected that the refrigerant will be cooled too much by the heat exchange in the subcooler 14, resulting in an increase in compression power.

[0208] 5, in the heating mode according to this embodiment, the flow of refrigerant into the sub-cooler 14 is blocked, thereby suppressing the effect of the outside air temperature Tam on the refrigerant, and heating the vehicle cabin can be achieved with appropriate compression power. That is, according to the vehicle air conditioning system 1 according to this embodiment, heating capacity and cooling capacity can be achieved according to the environment, including the outside air temperature Tam, and the operating mode when air-conditioning the vehicle cabin.

[0209] 1 and other figures, in the refrigeration cycle 10 according to this embodiment, a first expansion valve 15a corresponding to a flow rate adjusting unit is disposed on the outlet side of the subcooler 14. Therefore, by adjusting the throttle opening of the first expansion valve 15a, it is possible to adjust the flow rate of the refrigerant circulating through the subcooler 14. When the refrigerant flows through the subcooler 14, heat of the refrigerant is released and the refrigerant becomes a complete liquid phase, which makes it easier to control the state of the refrigerant circulating through the refrigeration cycle 10.

[0210] According to the vehicle air conditioning device 1 of this embodiment, by executing the control program shown in FIG. 7, if the outside air temperature Tam is lower than the first reference temperature KTaml (step S1: NO), the heating mode is executed in step S2.

[0211] As a result, in a low outside temperature environment where the outside temperature Tam is lower than the first reference temperature KTaml, the heating mode is executed in which the refrigerant is circulated without passing through the sub-cooler 14 to heat the blown air W. In other words, with the vehicle air conditioning device 1 according to this embodiment, the influence of the outside temperature Tam on the refrigerant can be reliably reduced, and heating of the vehicle interior can be achieved with appropriate compression power.

[0212] The vehicle air conditioner 1 according to this embodiment can also operate in a dehumidifying / heating mode shown in Fig. 6. In the dehumidifying / heating mode, the refrigerant flowing from one side of the branching portion 13 through the sub-cooler 14 and the interior evaporator 16 and the refrigerant flowing from the other side of the branching portion 13 through the chiller 17 are circulated in parallel.

[0213] This allows the degree of subcooling of the refrigerant flowing from one side of the branch section 13 to the subcooler 14 to be increased, thereby enabling the vehicle air conditioning system 1 to improve the dehumidification performance of the blown air W in the dehumidifying heating mode.

[0214] According to the vehicle air conditioning system 1 of this embodiment, by executing the control program shown in FIG. 7, if the outside air temperature Tam is equal to or higher than the first reference temperature KTaml and lower than the second reference temperature KTamh (step S3: YES), the dehumidifying heating mode is executed in step S4.

[0215] As a result, in an environment where the outside air temperature Tam is equal to or higher than the first reference temperature KTaml and lower than the second reference temperature KTamh, a dehumidifying heating mode is executed in which part of the high-pressure refrigerant is circulated through the sub-cooler 14 to dehumidify and heat the blown air W. In other words, the vehicle air conditioning system 1 according to this embodiment can achieve a dehumidifying heating operation in which the blown air W is dehumidified with an appropriate dehumidifying capacity according to the outside air temperature Tam.

[0216] 7, when the outside air temperature Tam is equal to or higher than the second reference temperature KTamh, the cooling mode is executed in step S5. As shown in FIG. 4, in the cooling mode according to this embodiment, the refrigerant can be circulated through the subcooler 14, so that the degree of subcooling of the refrigerant can be increased, thereby improving the dehumidifying capacity (i.e., cooling capacity) of the blown air W.

[0217] The vehicle air conditioner 1 according to this embodiment can execute a battery cooling mode shown in Fig. 8 and an air conditioning cooling mode shown in Fig. 9 as examples of the heat dissipation cooling mode. In the vehicle air conditioner 1 in the battery cooling mode, the flow of refrigerant into the subcooler 14 is blocked, as shown in Fig. 8. That is, in the battery cooling mode, the refrigerant circulates by flowing through the compressor 11, the heat medium refrigerant heat exchanger 12, the branching unit 13, the second expansion valve 15b, the chiller 17, the junction unit 19, and the compressor 11 in this order.

[0218] In the refrigeration cycle 10, when the refrigerant is circulated through the subcooler 14, heat exchange occurs between the refrigerant and the outside air OA in the subcooler 14. For example, if the outside air OA is at a low temperature, it is expected that the refrigerant will be cooled too much by the heat exchange in the subcooler 14, resulting in an increase in compression power.

[0219] 8, in the battery cooling mode according to this embodiment, the flow of refrigerant into the subcooler 14 is blocked, thereby suppressing the effect of the outside air temperature Tam on the refrigerant, and battery cooling can be achieved using the refrigeration cycle 10 with appropriate compression power. That is, according to the vehicle air conditioning system 1 according to this embodiment, cooling capacity can be achieved according to the environment, including the outside air temperature Tam, and the operating mode.

[0220] In addition, in the air conditioning cooling mode, the flow of refrigerant flowing from one side of the branching section 13 through the sub-cooler 14 and the indoor evaporator 16 and the flow of refrigerant flowing from the other side of the branching section 13 through the chiller 17 are circulated in parallel.

[0221] This allows the degree of subcooling of the refrigerant flowing from one side of the branch section 13 to the subcooler 14 to be increased, thereby enabling the vehicle air conditioning system 1 to improve the dehumidification performance of the blown air W in the air conditioning cooling mode.

[0222] Then, according to the vehicle air conditioner 1 of this embodiment, when a battery cooling command is received, which is output when it is determined that cooling of the battery 31, which is the second object to be cooled, is required, the vehicle air conditioner 1 executes the battery cooling mode shown in Fig. 8 or the air conditioning cooling mode shown in Fig. 9 according to the operating mode of the air conditioning operation mode. In other words, according to the vehicle air conditioner 1 of this embodiment, it is possible to realize the cooling operation of the second object to be cooled with an appropriate cooling capacity according to the state of the battery 31, which is the second object to be cooled.

[0223] The present disclosure is not limited to the above-described embodiments, and various modifications can be made as follows within the scope of the present disclosure.

[0224] In the above-described embodiment, the heat medium-refrigerant heat exchanger 12, which corresponds to the radiator, has a high-temperature heat medium as a heat dissipation target, and the subcooler 14, which corresponds to the auxiliary heat dissipation unit, has an outside air OA as a heat dissipation target, but the present disclosure is not limited to this. As long as the heat dissipation target in the radiator and the heat dissipation target in the auxiliary heat dissipation unit are different, and the respective targets belong to different temperature ranges, the technology disclosed herein can be applied.

[0225] In the above-described embodiment, the interior evaporator 16 that cools the blown air W as the first object to be cooled is used as the component corresponding to the first evaporator, and the chiller 17 that cools the low-temperature heat medium as the second object to be cooled is used as the component corresponding to the second evaporator. Various configurations can be used as the first evaporator and the second evaporator as long as they are evaporators that cool different objects to be cooled. The different objects to be cooled may be the same type of object, such as blown air supplied to the front side of the vehicle cabin and blown air supplied to the rear side of the vehicle cabin.

[0226] In the above-described embodiment, the battery 31 as a heat-generating device is cooled via the low-temperature heat medium cooled by the chiller 17, but the present invention is not limited to this. The object cooled by the low-temperature heat medium may include not only the battery 31 mounted on the vehicle, but also heat-generating devices that generate heat as the vehicle is driven (for example, an inverter, a motor generator, etc.).

[0227] In the above-described embodiment, the first and second expansion valves 15a and 15b, which are electric expansion valves with a fully closing function, are used as the components corresponding to the first and second pressure reducing units. However, this is not limiting. For example, the first and second pressure reducing units may be configured with a refrigerant flow rate adjusting unit capable of blocking the flow of refrigerant and a pressure reducing unit with a refrigerant pressure reducing function. A fully closing open / close valve may be used as the refrigerant flow rate adjusting unit, and a mechanical expansion valve or a capillary tube may be used as the pressure reducing unit.

[0228] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A refrigeration cycle (10) having: a compressor (11) that compresses and discharges a refrigerant; a heating section (20) including a radiator (12) that radiates heat from the high-pressure refrigerant compressed by the compressor, and that heats an object to be heated by the heat of the high-pressure refrigerant; a branching section (13) that branches the flow of the refrigerant flowing out from the radiator; an auxiliary heat radiating section (14) that radiates heat from one of the refrigerants flowing out from the branching section to an object to be cooled; a first pressure reducing section (15a) that reduces the pressure of the refrigerant flowing out from the auxiliary heat radiating section; a first evaporator (16) that evaporates the refrigerant depressurized in the first pressure reducing section to cool a first object to be cooled; a second pressure reducing section (15b) that depressurizes the other refrigerant flowing out from the branching section; and a second evaporator (17) that evaporates the refrigerant depressurized in the second pressure reducing section to cool a second object to be cooled; a heating mode in which the object to be heated is heated using the refrigerant discharged from the compressor as a heat source, and in which the inflow of refrigerant to the auxiliary heat dissipation section is blocked; and a cooling mode in which the first object to be cooled is cooled by the first evaporator, and in which the inflow of refrigerant to the second evaporator is blocked.

2. The refrigeration cycle device according to claim 1, further comprising a flow rate adjusting section (15a) at the outlet side of the auxiliary heat dissipation section for adjusting the flow rate of the refrigerant flowing through the auxiliary heat dissipation section.

3. The refrigeration cycle device according to claim 1 or 2, wherein the refrigeration cycle device operates in the heating mode when the temperature (Tam) of the heat dissipation object is lower than a predetermined first reference temperature (KTaml).

4. The refrigeration cycle device according to claim 1 or 2, wherein the refrigeration cycle device has an operating mode in which the first object to be cooled is cooled by the first evaporator and the object to be heated is heated by the heating section, and a parallel mode in which refrigerant is allowed to flow into the auxiliary heat dissipation section and refrigerant is allowed to flow into the second evaporator.

5. The refrigeration cycle device according to claim 4, wherein the refrigeration cycle device operates in the parallel mode when the temperature (Tam) of the heat dissipation object is lower than a second reference temperature (KTamh) that is set higher than the first reference temperature.

6. The refrigeration cycle device according to claim 1 or 2, wherein the heat of the refrigerant discharged from the compressor is dissipated to the outside, different from the object to be heated, and the refrigeration cycle device has a heat dissipation cooling mode that allows the refrigerant to flow into the second evaporator as an operating mode for cooling the second object to be cooled.

7. The refrigeration cycle device according to claim 6, wherein the refrigeration cycle device operates in the heat radiation cooling mode when a heat radiation cooling instruction indicating that the second object to be cooled needs to be cooled is received.

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