Heat pump cycle device

Abstract

A heat pump cycle device is provided with a compressor (11), an upstream-side branch section (12a), a heating section (13), an outside air heat exchange section (15), an upstream-side pressure reduction section (14a), a downstream-side pressure reduction section (14c), a bypass passage (21a), and a bypass-side flow rate adjustment section (14d). In a heating mode for heating an object to be heated, the refrigerant decompressed by the upstream-side decompression unit (14a) is caused to flow into the outside air heat exchange unit (15), and the refrigerant is caused to absorb heat of outside air in the outside air heat exchange unit (15). In a defrosting mode in which frost in the outside air heat exchange unit (15) is removed, the refrigerant branched at the upstream branch unit (12a) is caused to flow into the outside air heat exchange unit (15) to dissipate heat, and the refrigerant decompressed at the downstream pressure reduction unit (14c) is mixed with the refrigerant flowing out from the bypass flow rate adjustment unit (14d) to be sucked into the compressor (11).

Description

[0001] Cross-references of related applications

[0002] This application is based on Japanese patent application No. 2022-101833 filed on June 24, 2022, and the contents thereof are cited herein. Technical Field

[0003] The present invention relates to a heat pump cycle device capable of executing a defrosting mode operation for removing frost attached to an outdoor air heat exchange portion. Background Art

[0004] In the past, Patent Document 1 disclosed a heat pump circulation device that can perform a defrosting mode operation to remove frost attached to the outside air heat exchange portion when frost is generated in the outside air heat exchange portion where the refrigerant exchanges heat with the outside air. In the heat pump circulation device of Patent Document 1, so-called condensation heat defrosting is performed, and the high-temperature refrigerant discharged from the compressor flows into the outside air heat exchange portion, thereby melting and removing the frost attached to the outside air heat exchange portion.

[0005] Furthermore, in the heat pump cycle device of Patent Document 1, in order to quickly complete the defrosting of the outdoor air heat exchange portion, it is possible to switch to a heat absorption defrosting mode, in which, in addition to the compression operation of the compressor, waste heat from a heat generating device that generates heat during operation and heat generated by an electric heater can be used for defrosting. In the heat absorption defrosting mode, the heat generated by a heat absorbing source such as a heat generating device and an electric heater is absorbed by the low-pressure side refrigerant and used as defrosting heat for defrosting the outdoor air heat exchange portion.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2021-133795

[0009] However, in the heat pump cycle device of Patent Document 1, if the heat absorption source cannot generate sufficient heat for defrosting, there is a possibility that defrosting of the outdoor air heat exchange portion cannot be completed quickly. Summary of the invention

[0010] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a heat pump cycle device capable of quickly completing defrosting of an outdoor air heat exchange unit.

[0011] A heat pump cycle device according to one embodiment of the present invention includes a compressor, an upstream branching portion, a heating portion, an outdoor air heat exchange portion, an upstream pressure reducing portion, a downstream pressure reducing portion, a bypass passage, and a bypass flow rate adjusting portion.

[0012] The compressor compresses and discharges the refrigerant. The upstream branching section branches the flow of the refrigerant discharged from the compressor. The heating section uses the refrigerant flowing out of the outlet on one side of the upstream branching section as a heat source to heat the heating object. The outside air heat exchange section exchanges heat between the refrigerant and the outside air. The upstream pressure reducing section reduces the pressure of the refrigerant flowing into the outside air heat exchange section. The downstream pressure reducing section reduces the pressure of the refrigerant flowing out of the outside air heat exchange section. The bypass passage guides the refrigerant flowing out of the other outlet on the upstream branching section to the refrigerant passage on the compressor suction port side. The bypass side flow rate adjustment section adjusts the flow rate of the refrigerant flowing in the bypass passage.

[0013] In the heating mode in which the heating section heats the heating object, the refrigerant decompressed in the upstream decompressing section flows into the outdoor air heat exchange section, and absorbs heat of outdoor air in the outdoor air heat exchange section.

[0014] In addition, in the defrost mode for removing frost attached to the outside air heat exchange part, the refrigerant flowing out from the outflow port on one side of the upstream side branch part flows into the outside air heat exchange part to dissipate heat, and the refrigerant flowing out of the outside air heat exchange part is depressurized in the downstream side pressure reducing part, and the refrigerant depressurized in the downstream side pressure reducing part is mixed with the refrigerant flowing out of the bypass side flow adjusting part and is sucked into the compressor.

[0015] Thus, even if frost forms on the outside air heat exchange portion during the operation in the heating mode, the outside air heat exchange portion can be defrosted by performing the operation in the defrosting mode.

[0016] Furthermore, in the defrost mode, the refrigerant decompressed in the downstream pressure reducing unit is mixed with the refrigerant flowing out of the bypass flow regulating unit and sucked into the compressor. That is, in the defrost mode, the refrigerant decompressed in the downstream pressure reducing unit is mixed with the refrigerant having a higher enthalpy, so that the cycle is balanced.

[0017] Therefore, the refrigerant at the outlet side of the outside air heat exchanger can be made to have a lower enthalpy, and the heat dissipation of the refrigerant in the outside air heat exchanger can be increased. As a result, the heat dissipation from the refrigerant to the frost attached to the outside air heat exchanger can be increased, thereby quickly completing the defrosting of the outside air heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above-mentioned object and other objects, features and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.

[0019] Figure 1 It is a schematic overall configuration diagram of a vehicle air conditioning device according to one embodiment.

[0020] Figure 2 It is a schematic structural diagram of an indoor air conditioning unit according to one embodiment.

[0021] Figure 3 This is a block diagram showing an electric control unit of a vehicle air conditioning system according to an embodiment.

[0022] Figure 4 This is a flowchart of a subroutine of a control program according to one embodiment.

[0023] Figure 5 This is a schematic overall configuration diagram showing the flow of a refrigerant in a heat absorption defrosting mode of a heat pump cycle according to an embodiment.

[0024] Figure 6 This is a schematic overall configuration diagram showing the flow of the refrigerant in the heat-absorbing hot gas defrosting mode of the heat pump cycle according to one embodiment.

[0025] Figure 7 This is a Mollier diagram showing the state of the refrigerant in the heat absorption hot gas defrosting mode alone of the heat pump cycle according to one embodiment.

[0026] Figure 8 This is a Mollier diagram showing the state of the refrigerant in the heating heat absorption hot gas defrosting mode of the heat pump cycle according to one embodiment.

[0027] Fig. 9 This is a schematic overall configuration diagram showing the flow of the refrigerant and the like in the hot gas defrosting mode of the heat pump cycle according to one embodiment.

[0028] Fig.10 This is a Mollier diagram showing the state of the refrigerant in the hot gas defrosting mode alone of the heat pump cycle according to one embodiment.

[0029] Fig.11 This is a Mollier diagram showing the state of the refrigerant in the heating hot gas defrost mode of the heat pump cycle according to one embodiment. DETAILED DESCRIPTION

[0030] use Figures 1 to 11 , an embodiment of the heat pump circulation device involved in the present invention is described. In this embodiment, the heat pump circulation device involved in the present invention is applied to a vehicle air conditioning device 1 mounted on an electric vehicle. The electric vehicle is a vehicle that obtains driving force for traveling from an electric motor. The vehicle air conditioning device 1 performs air conditioning in the vehicle interior as the air-conditioned space, and adjusts the temperature of the vehicle-mounted equipment. Therefore, the vehicle air conditioning device 1 can be called an air conditioning device with a vehicle-mounted equipment temperature adjustment function, or a vehicle-mounted equipment temperature adjustment device with an air conditioning function.

[0031] In the vehicle air conditioner 1, the temperature of the vehicle-mounted device, specifically, the battery 70 is adjusted. The battery 70 is a secondary battery that stores power to be supplied to a plurality of vehicle-mounted devices that operate by electricity. The battery 70 is a battery pack formed by connecting a plurality of stacked battery elements electrically in series or in parallel. The battery element of this embodiment is a lithium ion battery.

[0032] The battery 70 is a heat generating device that generates heat during operation (i.e., during charging and discharging). The output of the battery 70 tends to decrease when the temperature is low, and the degradation tends to progress when the temperature is high. Therefore, it is necessary to maintain the temperature of the battery 70 within an appropriate temperature range (in this embodiment, 15° C. or higher and 55° C. or lower). Here, in the electric vehicle of this embodiment, the vehicle air conditioner 1 is used to adjust the temperature of the battery 70.

[0033] Furthermore, in the vehicle air conditioning device 1, when frost forms on the outside air heat exchanger 15 of the heat pump cycle 10 described later, the heat generated by the battery 70 can be used as a heat source for melting and removing the frost attached to the outside air heat exchanger 15. Therefore, the battery 70 becomes a heat sink for generating defrosting heat for defrosting the outside air heat exchanger 15.

[0034] The vehicle air conditioner 1 is configured to switch the operation mode for air conditioning the vehicle interior and adjusting the temperature of the battery 70. The vehicle air conditioner 1 includes a heat pump cycle 10, a low temperature side heat medium circuit 40, an indoor air conditioning unit 50, a control device 60, and the like.

[0035] First, use Figure 1 , the heat pump cycle 10 will be described. The heat pump cycle 10 is a vapor compression refrigeration cycle that adjusts the temperature of the supply air blown into the vehicle interior and the low-temperature side heat medium circulating in the low-temperature side heat medium circuit 40. The heat pump cycle 10 is configured to be able to switch the circuit structure of the refrigerant circuit according to the operation mode of the vehicle air conditioner 1 in order to perform air conditioning in the vehicle interior and temperature adjustment of the vehicle-mounted equipment.

[0036] In the heat pump cycle 10, HFO-based refrigerant (specifically, R1234yf) is used as a refrigerant. The heat pump cycle 10 constitutes a subcritical refrigeration cycle in which the pressure of the high-pressure side refrigerant does not exceed the critical pressure of the refrigerant. Refrigeration oil for lubricating the compressor 11 is mixed in the refrigerant. The refrigeration oil is a PAG oil that is compatible with the liquid phase refrigerant. A part of the refrigeration oil circulates in the heat pump cycle 10 together with the refrigerant.

[0037] The compressor 11 sucks in the refrigerant in the heat pump cycle 10, compresses it, and then discharges it. The compressor 11 is an electric compressor that rotates a fixed capacity type compression mechanism with a fixed discharge capacity driven by an electric motor. The rotation speed of the compressor 11 (i.e., the refrigerant discharge capacity) is controlled by a control signal output from a control device 60 described later.

[0038] The compressor 11 is disposed in a drive device room formed on the front side of the vehicle cabin. The drive device room forms a space where at least a part of a device for generating and adjusting a driving force for driving the vehicle (for example, a driving motor) is disposed.

[0039] The inlet side of the first three-way joint 12a is connected to the discharge port of the compressor 11. The first three-way joint 12a has three inlet and outlet ports that are connected to each other. As the first three-way joint 12a, a joint portion formed by joining a plurality of pipes or a joint portion formed by providing a plurality of refrigerant passages in a metal block or a resin block can be used.

[0040] Furthermore, the heat pump cycle 10 includes second to sixth three-way joints 12b to 12f as described later. The basic structures of the second to sixth three-way joints 12b to 12f are the same as those of the first three-way joint 12a.

[0041] These three-way joints serve as a branching portion for branching the flow of the refrigerant when one of the three inflow and outflow ports is used as an inflow port and the remaining two are used as outflow ports. In addition, when two of the three inflow and outflow ports are used as inflow ports and the remaining one is used as an outflow port, a converging portion for converging the flow of the refrigerant.

[0042] For example, the first three-way joint 12a serves as an upstream branching portion that branches the flow of the discharged refrigerant discharged from the compressor 11. The sixth three-way joint 12f serves as a bypass-side merging portion that merges the flow of the refrigerant flowing out of the cooling expansion valve 14c described later and the flow of the refrigerant flowing out of the bypass-side flow control valve 14d described later.

[0043] The refrigerant inlet side of the indoor condenser 13 is connected to one outlet of the first three-way joint 12a. One inlet side of the sixth three-way joint 12f is connected to the other outlet of the first three-way joint 12a. The refrigerant passage from the other outlet of the first three-way joint 12a to one inlet of the sixth three-way joint 12f is a bypass passage 21a. The bypass side flow control valve 14d is arranged in the bypass passage 21a.

[0044] The bypass side flow control valve 14d is a bypass side pressure reducing unit that reduces the pressure of the refrigerant flowing out of the other outflow port of the first three-way joint 12a (i.e., the other refrigerant branched by the first three-way joint 12a) in the hot gas heating mode described later. In addition, the bypass side flow control valve 14d is a bypass side flow control unit that adjusts the mass flow rate of the refrigerant flowing through the bypass passage 21a.

[0045] The bypass flow regulating valve 14d is an electrical variable throttling mechanism having a valve core that changes the throttling opening and an electric actuator that displaces the valve core. A stepping motor or a brushless motor can be used as the electric actuator. The operation of the bypass flow regulating valve 14d is controlled by a control signal output from the control device 60.

[0046] The bypass flow control valve 14d has a fully open function to fully open the valve and function only as a refrigerant passage without performing refrigerant decompression and flow control functions. The bypass flow control valve 14d has a fully closed function to close the refrigerant passage.

[0047] The heat pump cycle 10 includes a heating expansion valve 14a, a cooling expansion valve 14b, and a cooling expansion valve 14c as described below. The basic structures of the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 14c are the same as those of the bypass flow control valve 14d.

[0048] The heating expansion valve 14a, the cooling expansion valve 14b, the cooling expansion valve 14c, and the bypass flow control valve 14d can switch the refrigerant circuit by the above-mentioned full closing function. Therefore, the heating expansion valve 14a, the cooling expansion valve 14b, the cooling expansion valve 14c, and the bypass flow control valve 14d are operation mode switching parts that switch the operation mode by switching the refrigerant circuit.

[0049] Of course, the heating expansion valve 14a, the cooling expansion valve 14b, the cooling expansion valve 14c and the bypass flow control valve 14d may also be formed by combining a variable throttling mechanism without a full closing function and an on-off valve for opening and closing the throttling passage. In this case, each on-off valve is an operation mode switching unit.

[0050] The indoor condenser 13 is disposed in an air conditioning casing 51 of an indoor air conditioning unit 50 described later. The indoor condenser 13 is a heating heat exchanger that performs heat exchange between the exhaust refrigerant flowing out of one outlet of the first three-way joint 12a (i.e., the exhaust refrigerant branched from the first three-way joint 12a) and the supply air passing through the indoor evaporator 18 described later.

[0051] The indoor condenser 13 heats the supply air by dissipating the heat of the discharged refrigerant to the supply air. Therefore, the indoor condenser 13 is a heating unit that heats the supply air as a heating object using the discharged refrigerant branched from the first three-way joint 12a as a heat source.

[0052] The refrigerant outlet of the indoor condenser 13 is connected to the inlet side of the second three-way joint 12b. The inlet side of the heating expansion valve 14a is connected to one outlet of the second three-way joint 12b. One inlet side of the four-way joint 12x is connected to the other outlet of the second three-way joint 12b. The refrigerant passage from the other outlet of the second three-way joint 12b to one inlet of the four-way joint 12x is the high-pressure side passage 21b.

[0053] A high-pressure side opening and closing valve 22a is disposed on the high-pressure side passage 21b. The high-pressure side opening and closing valve 22a is an opening and closing valve for opening and closing the high-pressure side passage 21b. The high-pressure side opening and closing valve 22a is an electromagnetic valve whose opening and closing operation is controlled by a control voltage output from the control device 60. The high-pressure side opening and closing valve 22a can switch the refrigerant circuit by opening and closing the high-pressure side passage 21b. Therefore, the high-pressure side opening and closing valve 22a is an operation mode switching unit.

[0054] The four-way joint 12x is a joint part having four inflow and outflow ports connected to each other. As the four-way joint 12x, a joint part formed in the same manner as the above-mentioned three-way joint can be adopted. As the four-way joint 12x, a joint formed by combining two three-way joints can also be adopted.

[0055] The heating expansion valve 14a is an upstream pressure reducing unit that reduces the pressure of the refrigerant flowing into the outdoor air heat exchanger 15 in an outdoor air heat absorption heating mode described later.

[0056] The outlet of the heating expansion valve 14a is connected to the refrigerant inlet side of the outside air heat exchanger 15. The outside air heat exchanger 15 is an outside air heat exchange unit that exchanges heat between the refrigerant flowing out of the heating expansion valve 14a and the outside air blown by the outside air fan (not shown). The outside air heat exchanger 15 is arranged on the front side of the drive device room. Therefore, when the vehicle is running, the running wind flowing into the drive device room through the grille can contact the outside air heat exchanger 15.

[0057] The outdoor air heat exchanger 15 serves as an outdoor air heat dissipation unit for dissipating heat of the refrigerant to the outdoor air in a cooling mode described below, etc. Also, the outdoor air heat exchanger 15 serves as an outdoor air heat absorption unit for absorbing heat of the outdoor air in an outdoor air heat absorption heating mode, etc.

[0058] The inlet side of the third three-way joint 12c is connected to the refrigerant outlet of the outdoor heat exchanger 15. One outlet of the third three-way joint 12c is connected to the other inlet side of the four-way joint 12x via the first check valve 16a. One inlet side of the fourth three-way joint 12d is connected to the other outlet of the third three-way joint 12c. The refrigerant passage from the other outlet of the third three-way joint 12c to the one inlet of the fourth three-way joint 12d is the low-pressure side passage 21c.

[0059] A low-pressure side opening and closing valve 22b is disposed in the low-pressure side passage 21c. The low-pressure side opening and closing valve 22b is an opening and closing valve for opening and closing the low-pressure side passage 21c. The basic structure of the low-pressure side opening and closing valve 22b is the same as that of the high-pressure side opening and closing valve 22a. The low-pressure side opening and closing valve 22b can switch the refrigerant circuit by opening and closing the low-pressure side passage 21c. Therefore, the low-pressure side opening and closing valve 22b is an operation mode switching unit.

[0060] The first check valve 16a allows the refrigerant to flow from the third three-way joint 12c side to the four-way joint 12x side, and prohibits the refrigerant from flowing from the four-way joint 12x side to the third three-way joint 12c side.

[0061] One outflow port of the four-way joint 12x is connected to the refrigerant inlet side of the indoor evaporator 18 via the refrigeration expansion valve 14b. The refrigeration expansion valve 14b is an evaporator pressure reducing unit that reduces the pressure of the refrigerant flowing out of one outflow port of the four-way joint 12x in the cooling mode, etc. In addition, the refrigeration expansion valve 14b is an evaporator flow rate adjusting unit that adjusts the mass flow rate of the refrigerant flowing into the indoor evaporator 18.

[0062] The indoor evaporator 18 is disposed in the air conditioning casing 51 of the indoor air conditioning unit 50. The indoor evaporator 18 is a refrigeration heat exchanger that performs heat exchange between the low-pressure refrigerant decompressed by the refrigeration expansion valve 14b and the supply air blown into the vehicle interior from the indoor blower 52. In the indoor evaporator 18, the supply air is cooled by evaporating the low-pressure refrigerant and absorbing heat.

[0063] The refrigerant outlet of the indoor evaporator 18 is connected to the inlet side of one side of the fifth three-way joint 12e via the second check valve 16b. The second check valve 16b allows the refrigerant to flow from the refrigerant outlet side of the indoor evaporator 18 to the fifth three-way joint 12e side, and prohibits the refrigerant from flowing from the fifth three-way joint 12e side to the refrigerant outlet side of the indoor evaporator 18.

[0064] The other outlet of the four-way joint 12x is connected to the other inlet side of the sixth three-way joint 12f via the cooling expansion valve 14c. The inlet side of the refrigerant passage of the refrigerator 20 is connected to the outlet of the sixth three-way joint 12f.

[0065] The cooling expansion valve 14c is a chiller decompression unit that decompresses the refrigerant flowing into the chiller 20 in a cooling mode described later. The cooling expansion valve 14c is a chiller flow rate adjustment unit that adjusts the mass flow rate of the refrigerant flowing into the chiller 20 in a cooling mode.

[0066] In addition, the cooling expansion valve 14c becomes a downstream pressure reducing unit that reduces the pressure of the refrigerant flowing out of the outdoor air heat exchanger 15 and flowing into the refrigerator 20 during the defrosting mode described later. Moreover, the cooling expansion valve 14c is a downstream flow regulating unit that adjusts the mass flow rate of the refrigerant flowing out of the outdoor air heat exchanger 15 and flowing into the refrigerator 20.

[0067] The cold machine 20 is a cooling heat exchange unit that exchanges heat between the low-pressure refrigerant after the pressure reduction by the cooling expansion valve 14c and the low-temperature side heat medium circulating in the low-temperature side heat medium circuit 40. The cold machine 20 cools the low-temperature side heat medium by evaporating the low-pressure refrigerant and absorbing heat. In addition, the cold machine 20 becomes a defrosting heat absorption unit that allows the low-pressure side refrigerant to absorb the defrosting heat generated by the battery 70 through the low-temperature side heat medium during the defrosting mode.

[0068] The other inlet side of the fourth three-way joint 12d is connected to the outlet of the refrigerant passage of the cold machine 20. The other inlet side of the fifth three-way joint 12e is connected to the outlet of the fourth three-way joint 12d.

[0069] The inlet side of the accumulator 23 is connected to the outflow port of the fifth three-way joint 12e. The accumulator 23 is a gas-liquid separator configured to separate the refrigerant flowing into the inside into gas and liquid, and to make the separated gas-phase refrigerant flow out to the suction port side of the compressor 11, while accumulating the separated liquid-phase refrigerant as the low-pressure side of the circulating surplus refrigerant. The gas-phase refrigerant outlet of the accumulator 23 is connected to the suction port side of the compressor 11.

[0070] Next, the low temperature side heat medium circuit 40 is described. The low temperature side heat medium circuit 40 is a heat medium circuit that circulates the low temperature side heat medium. In this embodiment, an ethylene glycol aqueous solution is used as the low temperature side heat medium. The low temperature side heat medium circuit 40 is connected to the low temperature side pump 41, the cooling water passage 70a of the battery 70, the heat medium passage of the cold machine 20, etc.

[0071] The low temperature side pump 41 is a low temperature side heat medium pressure delivery unit that pressure delivers the low temperature side heat medium flowing out of the cooling water passage 70a of the battery 70 to the inlet side of the heat medium passage of the cold machine 20. The low temperature side pump 41 is an electric pump whose rotation speed (i.e., pressure delivery capacity) is controlled by a control voltage output from the control device 60. The inlet side of the cooling water passage 70a of the battery 70 is connected to the outlet side of the heat medium passage of the cold machine 20.

[0072] The cooling water passage 70a of the battery 70 is formed to cool the battery 70 by circulating the low-temperature side heat medium cooled by the refrigerator 20. The cooling water passage 70a is formed inside a battery-specific case that accommodates a plurality of stacked battery elements.

[0073] The cooling water passage 70a has a passage structure in which a plurality of passages are connected in parallel inside the battery-dedicated housing. Thus, all battery elements can be cooled uniformly in the cooling water passage 70a. The outlet of the cooling water passage 70a is connected to the suction port side of the low-temperature side pump 41.

[0074] In the low-temperature-side heat medium circuit 40 , the amount of heat exchange between the refrigerant and the low-temperature-side heat medium in the refrigerator 20 can be changed by changing the rotation speed of the low-temperature-side pump 41 .

[0075] Therefore, the low temperature side pump 41 is an operation mode switching unit that switches the operation mode by changing the heat exchange amount between the refrigerant and the low temperature side heat medium in the cold machine 20. More specifically, it is an operation mode switching unit that switches the operation mode by switching whether to allow the refrigerant and the low temperature side heat medium to exchange heat in the cold machine 20.

[0076] Next, use Figure 2 , the indoor air conditioning unit 50 is described. The indoor air conditioning unit 50 is a unit formed by integrating a plurality of components in order to blow the supply air adjusted to an appropriate temperature to an appropriate part in the vehicle interior for air conditioning in the vehicle interior. The indoor air conditioning unit 50 is arranged on the inner side of the instrument panel (dashboard) at the frontmost part in the vehicle interior.

[0077] The indoor air conditioning unit 50 is formed by accommodating an indoor blower 52, an indoor evaporator 18, an indoor condenser 13, etc. in an air conditioning case 51 forming an air passage for supplying air. The air conditioning case 51 is formed of a resin (for example, polypropylene) having a certain degree of elasticity and excellent strength.

[0078] An inside-outside air switching device 53 is disposed on the most upstream side of the air supply flow of the air conditioning housing 51. The inside-outside air switching device 53 switches between introducing inside air (i.e., air inside the vehicle interior) and outside air (i.e., air outside the vehicle exterior) into the air conditioning housing 51. The operation of the inside-outside air switching device 53 is controlled by a control signal output from the control device 60.

[0079] An indoor blower 52 is disposed downstream of the blown air flow of the indoor and outdoor air switching device 53. The indoor blower 52 is a blower that blows the air sucked in through the indoor and outdoor air switching device 53 toward the vehicle interior. The rotation speed (i.e., the blower capacity) of the indoor blower 52 is controlled by a control voltage output from the control device 60.

[0080] An indoor evaporator 18 and an indoor condenser 13 are arranged on the downstream side of the supply air flow of the indoor blower 52. The indoor evaporator 18 is arranged on the upstream side of the supply air flow compared with the indoor condenser 13. A cold air bypass passage 55 is formed in the air conditioning casing 51 so that the supply air passing through the indoor evaporator 18 bypasses the indoor condenser 13.

[0081] An air mix door 54 is disposed in the air conditioning case 51 on the downstream side of the supply air flow of the indoor evaporator 18 and on the upstream side of the supply air flow of the indoor condenser 13 and the cold air bypass passage 55 .

[0082] The air mix door 54 adjusts the air volume ratio of the supply air passing through the indoor condenser 13 side and the supply air passing through the cold air bypass passage 55 after passing through the indoor evaporator 18. The operation of the actuator for driving the air mix door 54 is controlled by a control signal output from the control device 60.

[0083] Therefore, in the indoor air conditioning unit 50 , by changing the opening degree of the air mix door 54 , the amount of heat exchange between the refrigerant and the supply air in the indoor condenser 13 can be changed.

[0084] Therefore, the air mix door 54 is an operation mode switch that switches the operation mode by changing the amount of heat exchange between the refrigerant and the supply air in the indoor condenser 13. More specifically, it is an operation mode switch that switches the operation mode by switching whether the refrigerant and the supply air perform heat exchange in the indoor condenser 13.

[0085] A mixing space 56 is disposed downstream of the indoor condenser 13 and the cold air bypass passage 55 in the supply air flow. The mixing space 56 is a space where the supply air heated by the indoor condenser 13 and the supply air that has passed through the cold air bypass passage 55 and is not heated are mixed.

[0086] Therefore, in the interior air conditioning unit 50 , by adjusting the opening degree of the air mix door 54 , it is possible to adjust the temperature of the supply air (ie, conditioned air) mixed in the mixing space 56 and blown into the vehicle interior.

[0087] A plurality of openings (not shown) for blowing out the conditioned air toward various locations in the vehicle interior are formed at the most downstream portion of the air supply air flow of the air conditioning housing 51. A blow-out mode door (not shown) for opening and closing each of the openings is disposed at the plurality of openings. The operation of the actuator for driving the blow-out mode door is controlled by a control signal output from the control device 60.

[0088] Therefore, in the interior air conditioning unit 50, by switching the opening hole opened and closed by the blow-out mode door, conditioned air adjusted to an appropriate temperature can be blown to an appropriate location in the vehicle interior.

[0089] Next, use Figure 3 The electric control unit of this embodiment is described with reference to the block diagram of FIG. 60. The control device 60 has a well-known microcomputer including a CPU, a ROM, a RAM, etc. and its peripheral circuits. The control device 60 performs various calculations and processes based on the control program stored in the ROM. In addition, the control device 60 controls the operation of various control target devices connected to the output side based on the calculation and processing results.

[0090] A sensor group for control, such as an indoor air temperature sensor 61a, an outdoor air temperature sensor 61b, a sunlight sensor 61c, a discharge refrigerant temperature and pressure sensor 62a, a high-pressure side refrigerant temperature and pressure sensor 62b, an outdoor air side refrigerant temperature and pressure sensor 62c, an evaporator side refrigerant temperature and pressure sensor 62d, a cold machine side refrigerant temperature and pressure sensor 62e, a low-temperature side heat medium temperature sensor 63b, a battery temperature sensor 64, and an air conditioning wind temperature sensor 65, is connected to the input side of the control device 60.

[0091] The indoor air temperature sensor 61a is an indoor air temperature detection unit that detects the vehicle interior temperature (indoor air temperature) Tr. The outdoor air temperature sensor 61b is an outdoor air temperature detection unit that detects the vehicle exterior temperature (outdoor air temperature) Tam. The sunlight sensor 61c is a sunlight amount detection unit that detects the sunlight amount As irradiated into the vehicle interior.

[0092] The discharged refrigerant temperature and pressure sensor 62 a is a discharged refrigerant temperature and pressure detecting unit that detects a discharged refrigerant temperature Td and a discharged refrigerant pressure Pd of the discharged refrigerant discharged from the compressor 11 .

[0093] The high-pressure-side refrigerant temperature and pressure sensor 62 b is a high-pressure-side refrigerant temperature and pressure detection unit that detects the high-pressure-side refrigerant temperature T1 and the high-pressure-side refrigerant pressure P1 of the refrigerant flowing out of the indoor condenser 13 .

[0094] The outdoor air side refrigerant temperature and pressure sensor 62 c is an outdoor unit side refrigerant temperature and pressure detection unit that detects the outdoor air side refrigerant temperature T2 and the outdoor air side refrigerant pressure P2 of the refrigerant flowing out of the outdoor air heat exchanger 15 .

[0095] The evaporator-side refrigerant temperature and pressure sensor 62 d is an evaporator-side refrigerant temperature and pressure detection unit that detects the evaporator-side refrigerant temperature Te and the evaporator-side refrigerant pressure Pe of the refrigerant flowing out of the indoor evaporator 18 .

[0096] The chiller-side refrigerant temperature and pressure sensor 62 e is a chiller-side refrigerant temperature and pressure detection unit that detects the chiller-side refrigerant temperature Tc and the chiller-side refrigerant pressure Pc of the refrigerant flowing out of the refrigerant passage of the chiller 20 .

[0097] In the present embodiment, a pressure detection portion and a temperature detection portion integrated as the refrigerant temperature and pressure sensor are used, but it is apparent that a pressure detection portion and a temperature detection portion constructed separately may be used.

[0098] The low-temperature-side heat medium temperature sensor 63 b is a low-temperature-side heat medium temperature detection unit that detects a low-temperature-side heat medium temperature TWL that is the temperature of the low-temperature-side heat medium flowing into the heat medium passage of the chiller 20 .

[0099] The battery temperature sensor 64 is a battery temperature detection unit that detects a battery temperature TB, which is the temperature of the battery 70. The battery temperature sensor 64 includes a plurality of temperature sensors and detects the temperatures of a plurality of locations of the battery 70. Therefore, the control device 60 can detect the temperature difference and temperature distribution of each battery element forming the battery 70. In addition, the average value of the detection values ​​of the plurality of temperature sensors is used as the battery temperature TB.

[0100] The conditioned air temperature sensor 65 is a conditioned air temperature detection unit that detects the supply air temperature TAV, which is the temperature of the supply air blown from the mixing space 56 into the vehicle interior.

[0101] Moreover, if Figure 3 As shown, an operation panel 69 disposed near the instrument panel in the front part of the vehicle cabin is connected to the input side of the control device 60. Various operation switches for the occupant to operate are provided on the operation panel 69. The control device 60 receives operation signals from the various operation switches.

[0102] Specific examples of the various operation switches provided on the operation panel 69 include an automatic switch, an air conditioning switch, a heating switch, an air volume setting switch, a temperature setting switch, and the like.

[0103] The automatic switch is an automatic control setting unit for setting or releasing the automatic control operation of the vehicle air conditioner 1. The air conditioning switch is a cooling request unit for requesting the indoor evaporator 18 to cool the supply air. The heating switch is a heating request unit for requesting the indoor condenser 13 to heat the supply air. The air volume setting switch is an air volume setting unit for manually setting the air volume of the indoor blower 52. The temperature setting switch is a temperature setting unit for setting the set temperature Tset in the vehicle interior.

[0104] Here, the control device 60 of this embodiment is integrally constituted by a control unit that controls various control target devices connected to its output side. Therefore, the structure (hardware and software) that controls the operation of each control target device constitutes the control unit that controls the operation of each control target device.

[0105] For example, the configuration of the control device 60 that controls the rotation speed of the compressor 11 constitutes the compressor control unit 60a. The configuration that controls the operation of the operation mode switching unit constitutes the operation mode control unit 60b.

[0106] Next, the operation of the vehicle air conditioner 1 of the present embodiment in the above-described configuration will be described. In the vehicle air conditioner 1, various operation modes are switched to perform air conditioning in the vehicle interior and temperature adjustment of the battery 70. The operation mode is switched by executing a control program pre-stored in the control device 60.

[0107] The control program is executed when a start switch (so-called ignition switch) of the vehicle system is triggered to start the vehicle system, and when the battery 70 is charged from an external power source.

[0108] In the control program, the detection signal of the above-mentioned control sensor group and the operation signal of the operation panel 69 are read. And the target blow-out temperature TAO, which is the target temperature of the supply air blown into the vehicle interior, is calculated based on the read detection signal and operation signal. Furthermore, the operation mode is selected based on the detection signal, the operation signal, the target blow-out temperature TAO, etc., and the operation of various control object devices is controlled according to the selected operation mode.

[0109] Afterwards, until the end condition of the control program is met, the control process of reading the above-mentioned detection signals and operation signals, calculating the target blow-out temperature TAO, selecting the operation mode and controlling various control object devices is repeated in each specified control cycle.

[0110] The target outlet temperature TAO is calculated using the following mathematical formula F1.

[0111] TAO=Kset×Tset-Kr×Tr-Kam×Tam-Ks×As+C…(F1)

[0112] Tset is the set temperature in the vehicle cabin set by the temperature setting switch. Tr is the indoor air temperature detected by the indoor air temperature sensor 61a. Tam is the outdoor air temperature detected by the outdoor air temperature sensor 61b. As is the amount of sunlight detected by the sunlight amount sensor 61c. Kset, Kr, Kam, and Ks are control gains, and C is a constant for correction. The following describes each operation mode.

[0113] (a) Cooling mode

[0114] The cooling mode is an operation mode for cooling the vehicle interior by blowing cooled supply air into the vehicle interior. The cooling mode is easily selected when the outside air temperature Tam becomes high and the target outlet temperature TAO becomes low when the automatic switch and the air conditioning switch are turned on.

[0115] The cooling mode includes a cooling mode alone for cooling the vehicle interior without cooling the battery 70 and a cooling-cooling mode for cooling the vehicle interior while cooling the battery 70. In the control routine of the present embodiment, when the battery temperature TB detected by the battery temperature sensor 64 becomes equal to or higher than a preset reference upper limit temperature KTBH, the operation mode for cooling the battery 70 is executed.

[0116] (a-1) Single cooling mode

[0117] In the heat pump cycle 10 in the cooling-only mode, the control device 60 sets the heating expansion valve 14a to a fully open state, sets the cooling expansion valve 14b to a throttling state that exerts a refrigerant decompression effect, sets the cooling expansion valve 14c to a fully closed state, and sets the bypass side flow control valve 14d to a fully closed state. In addition, the control device 60 closes the high-pressure side on-off valve 22a and closes the low-pressure side on-off valve 22b.

[0118] Therefore, in the heat pump cycle 10 in the single cooling mode, the refrigerant circuit is switched so that the refrigerant discharged from the compressor 11 circulates in the order of the indoor condenser 13, the heating expansion valve 14a which is in a fully open state, the outdoor air heat exchanger 15, the cooling expansion valve 14b which is in a throttling state, the indoor evaporator 18, the accumulator 23, and the suction port of the compressor 11.

[0119] In the indoor air conditioning unit 50 in the cooling-only mode, the control device 60 controls the rotation speed of the indoor fan 52 based on the target air outlet temperature TAO with reference to a control map pre-stored in the control device 60 .

[0120] The control device 60 also adjusts the opening of the air mix door 54 so that the supply air temperature TAV detected by the conditioned air temperature sensor 65 approaches the target outlet temperature TAO. The control device 60 also appropriately controls the operations of other control target devices.

[0121] Therefore, in the heat pump cycle 10 in the cooling mode alone, a vapor compression refrigeration cycle is configured in which the indoor condenser 13 and the outdoor air heat exchanger 15 function as condensers for condensing the refrigerant by dissipating heat, and the indoor evaporator 18 functions as an evaporator for evaporating the refrigerant. Here, in the operation mode in which the refrigerant is evaporated by the indoor evaporator 18, the evaporation temperature of the refrigerant in the indoor evaporator 18 is adjusted within a range that can suppress frost on the indoor evaporator 18.

[0122] In the indoor air conditioning unit 50 in the cooling mode alone, the supply air blown from the indoor blower 52 is cooled in the indoor evaporator 18. The supply air cooled in the indoor evaporator 18 is heated again by heat exchange with the refrigerant in the indoor condenser 13 according to the opening degree of the air mix door 54. Then, the supply air whose temperature is adjusted so as to be close to the target blowing temperature TAO is blown into the vehicle interior, thereby cooling the vehicle interior.

[0123] (a-2) Cooling mode

[0124] In the heat pump cycle 10 in the cooling mode, the control device 60 sets the cooling expansion valve 14c to the throttling state with respect to the cooling-only mode.

[0125] Therefore, in the heat pump cycle 10 in the cooling refrigeration mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single cooling mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which the refrigerant circulates in the order of the indoor condenser 13, the heating expansion valve 14a in the fully open state, the outdoor air heat exchanger 15, the cooling expansion valve 14c in the throttle state, the chiller 20, the accumulator 23, and the suction port of the compressor 11. That is, the refrigerant circuit is switched to a refrigerant circuit in which the indoor evaporator 18 and the chiller 20 are connected in parallel with respect to the flow of the refrigerant.

[0126] In addition, in the low temperature side heat medium circuit 40 of the cooling and refrigeration mode, the control device 60 operates the low temperature side pump 41 to exert the preset reference pressure delivery capacity. Therefore, in the low temperature side heat medium circuit 40 of the cooling and refrigeration mode, the low temperature side heat medium pressure-delivered from the low temperature side pump 41 circulates in the order of the heat medium passage of the chiller 20, the cooling water passage 70a of the battery 70, and the suction port of the low temperature side pump 41.

[0127] In the indoor air conditioning unit 50 in the cooling mode, the control device 60 controls the rotation speed of the indoor blower 52, the opening degree of the air mix door 54, etc., similarly to the cooling mode alone. The control device 60 also appropriately controls the operation of other control target devices.

[0128] Therefore, in the heat pump cycle 10 in the cooling mode, a vapor compression refrigeration cycle is constructed in which the indoor condenser 13 and the outdoor air heat exchanger 15 function as condensers, and the indoor evaporator 18 and the refrigerator 20 function as evaporators.

[0129] In the low-temperature side heat medium circuit 40 in the cooling refrigeration mode, the low-temperature side heat medium flowing into the heat medium passage of the refrigerator 20 exchanges heat with the low-pressure side refrigerant after being decompressed by the cooling expansion valve 14c and is cooled. The low-temperature side heat medium cooled in the refrigerator 20 flows into the cooling water passage 70a of the battery 70.

[0130] The low temperature side heat medium flowing into the cooling water passage 70a of the battery 70 absorbs the heat generated by the battery 70. As a result, the battery 70 is cooled. The low temperature side heat medium flowing out of the cooling water passage 70a of the battery 70 is sucked into the low temperature side pump 41 and pressure-fed to the heat medium passage of the refrigerator 20.

[0131] In the cooling mode, the interior air conditioning unit 50 cools the interior of the vehicle by blowing the supply air whose temperature has been adjusted into the interior of the vehicle, similarly to the cooling-only mode.

[0132] (b) Dehumidification and heating mode

[0133] The dehumidification and heating mode is an operation mode for dehumidifying and heating the vehicle interior by reheating the cooled and dehumidified supply air and blowing it into the vehicle interior. The dehumidification and heating mode is easily selected when the automatic switch and the air conditioning switch are turned on, when the outside air temperature Tam is in the middle temperature range, and when the target outlet temperature TAO is in the middle temperature range.

[0134] The dehumidification and heating mode includes a single dehumidification and heating mode in which dehumidification and heating of the vehicle interior is performed without cooling the battery 70 , and a cooling and dehumidification and heating mode in which dehumidification and heating of the vehicle interior is performed while cooling the battery 70 .

[0135] (b-1) Dehumidification and heating mode only

[0136] In the heat pump cycle 10 in the single dehumidification and heating mode, the control device 60 sets the heating expansion valve 14a to the throttling state, sets the cooling expansion valve 14b to the throttling state, sets the cooling expansion valve 14c to the fully closed state, and sets the bypass side flow control valve 14d to the fully closed state. In addition, the control device 60 closes the high-pressure side on-off valve 22a and closes the low-pressure side on-off valve 22b.

[0137] Therefore, in the heat pump cycle 10 in the separate dehumidification and heating mode, the refrigerant circuit is switched to one in which the refrigerant discharged from the compressor 11 circulates in the order of the indoor condenser 13, the heating expansion valve 14a which is in a throttling state, the outdoor air heat exchanger 15, the cooling expansion valve 14b which is in a throttling state, the indoor evaporator 18, the accumulator 23, and the suction port of the compressor 11.

[0138] In the indoor air conditioning unit 50 in the dehumidification heating only mode, the control device 60 controls the rotation speed of the indoor blower 52, the opening degree of the air mix door 54, etc., similarly to the cooling only mode. The control device 60 also appropriately controls the operation of other control target devices.

[0139] Therefore, in the heat pump cycle 10 in the dehumidification heating mode alone, a vapor compression refrigeration cycle is configured in which the indoor condenser 13 functions as a condenser and the indoor evaporator 18 functions as an evaporator.

[0140] Furthermore, in the dehumidification and heating mode alone, when the saturation temperature of the refrigerant in the outdoor air heat exchanger 15 is higher than the outdoor air temperature Tam, the outdoor air heat exchanger 15 is made to function as a condenser. In addition, when the saturation temperature of the refrigerant in the outdoor air heat exchanger 15 is lower than the outdoor air temperature Tam, the outdoor air heat exchanger 15 is made to function as an evaporator.

[0141] In the indoor air conditioning unit 50 in the dehumidification and heating mode alone, the supply air blown from the indoor blower 52 is cooled and dehumidified in the indoor evaporator 18. The supply air cooled and dehumidified in the indoor evaporator 18 is heated again in the indoor condenser 13 according to the opening degree of the air mix door 54. Then, the supply air whose temperature is adjusted so as to be close to the target outlet temperature TAO is blown into the vehicle interior, thereby achieving dehumidification and heating in the vehicle interior.

[0142] (b-2) Cooling, dehumidification and heating mode

[0143] In the heat pump cycle 10 in the cooling, dehumidification and heating mode, the control device 60 sets the cooling expansion valve 14c to the throttling state with respect to the dehumidification and heating alone mode.

[0144] Therefore, in the heat pump cycle 10 in the cooling dehumidification heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single dehumidification heating mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which the refrigerant circulates in the order of the indoor condenser 13, the heating expansion valve 14a in the throttle state, the outdoor air heat exchanger 15, the cooling expansion valve 14c in the throttle state, the chiller 20, the accumulator 23, and the suction port of the compressor 11. That is, the refrigerant circuit is switched to a refrigerant circuit in which the indoor evaporator 18 and the chiller 20 are connected in parallel with respect to the flow of the refrigerant.

[0145] In addition, in the low temperature side heat medium circuit 40 of the cooling dehumidification and heating mode, the control device 60 operates the low temperature side pump 41 as in the cooling refrigeration mode. Therefore, in the low temperature side heat medium circuit 40 of the cooling dehumidification and heating mode, the low temperature side heat medium pumped from the low temperature side pump 41 circulates as in the cooling refrigeration mode.

[0146] In the indoor air conditioning unit 50 in the cooling, dehumidifying and heating mode, the control device 60 controls the rotation speed of the indoor blower 52, the opening degree of the air mix door 54, etc., similarly to the cooling mode alone. The control device 60 also appropriately controls the operation of other control target devices.

[0147] Therefore, in the heat pump cycle 10 in the cooling dehumidification and heating mode, similarly to the single dehumidification and heating mode, a vapor compression refrigeration cycle is constructed in which the indoor condenser 13 functions as a condenser and the indoor evaporator 18 and the refrigerator 20 function as evaporators.

[0148] Moreover, in the cooling dehumidification and heating mode, similarly to the single dehumidification and heating mode, when the saturation temperature of the refrigerant in the outdoor air heat exchanger 15 is higher than the outdoor air temperature Tam, the outdoor air heat exchanger 15 is made to function as a condenser. In addition, when the saturation temperature of the refrigerant in the outdoor air heat exchanger 15 is lower than the outdoor air temperature Tam, the outdoor air heat exchanger 15 is made to function as an evaporator.

[0149] In the low-temperature side heat medium circuit 40 in the cooling, dehumidification and heating mode, similarly to the cooling and refrigeration mode, the low-temperature side heat medium cooled in the refrigerator 20 flows into the cooling water passage 70a of the battery 70. Thus, the battery 70 is cooled.

[0150] In the interior air conditioning unit 50 in the cooling, dehumidification and heating mode, similarly to the dehumidification and heating alone mode, the temperature-adjusted supply air is blown into the vehicle interior, thereby achieving dehumidification and heating in the vehicle interior.

[0151] (c) External air absorption heating mode

[0152] The outdoor air heat absorption heating mode is an operation mode for heating the interior of the vehicle by blowing the heated supply air into the vehicle interior. The outdoor air heat absorption heating mode is easily selected when the outdoor air temperature Tam becomes low and the target blow-out temperature TAO becomes a relatively high value when the automatic switch is turned on. In addition, it is selected when the heating switch of the operation panel is turned on.

[0153] In the outdoor air heat absorption heating mode, the refrigerant decompressed by the heating expansion valve 14a flows into the outdoor air heat exchanger 15, and the refrigerant absorbs heat from the outdoor air in the outdoor air heat exchanger 15. Then, the heat absorbed by the refrigerant from the outdoor air is used as a heat source to heat the supply air in the heating unit. Therefore, the outdoor air heat absorption heating mode is a heating mode for heating a heating object.

[0154] The outside air absorption heating mode includes a single outside air absorption heating mode for heating the vehicle interior without cooling the battery 70 and a cooling outside air absorption heating mode for heating the vehicle interior while cooling the battery 70 .

[0155] (c-1) External air absorption heating mode only

[0156] In the heat pump cycle 10 in the external air heat absorption heating mode alone, the control device 60 sets the heating expansion valve 14a to the throttling state, sets the cooling expansion valve 14b to the fully closed state, sets the cooling expansion valve 14c to the fully closed state, and sets the bypass side flow control valve 14d to the fully closed state. In addition, the control device 60 closes the high-pressure side on-off valve 22a and opens the low-pressure side on-off valve 22b.

[0157] Therefore, in the heat pump cycle 10 in the single outdoor air heat absorption heating mode, the refrigerant circuit is switched to one in which the refrigerant discharged from the compressor 11 circulates in the order of the indoor condenser 13, the heating expansion valve 14a which is in a throttling state, the outdoor air heat exchanger 15, the low-pressure side passage 21c, the liquid storage tank 23, and the suction port of the compressor 11.

[0158] The controller 60 controls the rotation speed of the compressor 11 so that the discharge refrigerant pressure Pd detected by the discharge refrigerant temperature pressure sensor 62a approaches the heating target pressure PDO. The heating target pressure PDO is set so that the supply air can be heated appropriately in the indoor condenser 13.

[0159] In addition, the control device 60 adjusts the throttling opening of the cooling expansion valve 14c so that the degree of subcooling SC1 of the refrigerant flowing out of the indoor condenser 13 approaches the target degree of subcooling SCO. The degree of subcooling SC1 can be obtained based on the high-pressure side refrigerant temperature T1 and the high-pressure side refrigerant pressure P1 detected by the high-pressure side refrigerant temperature and pressure sensor 62b. The target degree of subcooling SCO is determined in such a way that the coefficient of refrigeration (COP) of the cycle approaches a maximum value.

[0160] In the indoor air conditioning unit 50 in the outdoor heat absorption heating mode alone, the control device 60 controls the rotation speed of the indoor blower 52, the opening degree of the air mix door 54, etc., similarly to the cooling mode alone. The control device 60 also appropriately controls the operation of other control target devices.

[0161] Therefore, in the heat pump cycle 10 in the outdoor air heat absorption heating mode alone, a vapor compression refrigeration cycle is configured in which the indoor condenser 13 functions as a condenser and the outdoor air heat exchanger 15 functions as an evaporator. Here, in the outdoor air heat absorption heating mode, it is necessary to allow the refrigerant to absorb the heat of the outdoor air in the outdoor air heat exchanger 15. Therefore, the evaporation temperature of the refrigerant in the outdoor air heat exchanger 15 in the outdoor air heat absorption heating mode is lower than the outdoor air temperature Tam.

[0162] In the indoor air conditioning unit 50 in the outdoor air absorption heating mode alone, the supply air blown from the indoor blower 52 passes through the indoor evaporator 18. The supply air that has passed through the indoor evaporator 18 is heated in the indoor condenser 13 according to the opening degree of the air mix door 54. Then, the supply air whose temperature is adjusted so as to be close to the target outlet temperature TAO is blown into the vehicle interior, thereby achieving heating of the vehicle interior.

[0163] (c-2) Cooling and heating mode

[0164] In the heat pump cycle 10 in the cooling outside air heat absorption heating mode, the control device 60 sets the cooling expansion valve 14c to the throttling state with respect to the outside air heat absorption heating mode alone. In addition, the control device 60 opens the high-pressure side on-off valve 22a.

[0165] Therefore, in the heat pump cycle 10 in the cooling outside air heat absorption heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the single outside air heat absorption heating mode. At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which the refrigerant circulates in the order of the indoor condenser 13, the high-pressure side passage 21b, the cooling expansion valve 14c in the throttle state, the chiller 20, the accumulator 23, and the suction port of the compressor 11. That is, the refrigerant circuit is switched to a refrigerant circuit in which the outside air heat exchanger 15 and the chiller 20 are connected in parallel with respect to the flow of the refrigerant.

[0166] In addition, in the low temperature side heat medium circuit 40 of the cooling outside air heat absorption heating mode, the control device 60 operates the low temperature side pump 41 as in the cooling refrigeration mode. Therefore, in the low temperature side heat medium circuit 40 of the cooling outside air heat absorption heating mode, the low temperature side heat medium pumped from the low temperature side pump 41 circulates as in the cooling refrigeration mode.

[0167] In the indoor air conditioning unit 50 in the outdoor air cooling and heat absorption heating mode, the control device 60 controls the rotation speed of the indoor blower 52, the opening degree of the air mix door 54, etc., as in the cooling mode alone. The control device 60 also appropriately controls the operation of other control target devices.

[0168] Therefore, in the heat pump cycle 10 in the cooling outside air heat absorption heating mode, a vapor compression refrigeration cycle is configured in which the indoor condenser 13 functions as a condenser and the outside air heat exchanger 15 and the refrigerator 20 function as evaporators.

[0169] In the low-temperature side heat medium circuit 40 in the cooling outdoor air heat absorption heating mode, similarly to the cooling refrigeration mode, the low-temperature side heat medium cooled in the refrigerator 20 flows into the cooling water passage 70a of the battery 70. Thus, the battery 70 is cooled.

[0170] In the indoor air conditioning unit 50 in the cooling outside air heat absorption heating mode, similarly to the outside air heat absorption heating mode alone, the temperature-adjusted supply air is blown into the vehicle interior, thereby heating the vehicle interior.

[0171] (d) Hot air heating mode

[0172] The hot air heating mode is an operation mode for heating the vehicle interior and is selected when the outside air temperature Tam reaches an extremely low temperature (less than -10°C in the present embodiment) with the automatic switch turned on.

[0173] In the heat pump cycle 10 in the hot gas heating mode, the control device 60 sets the heating expansion valve 14a to a fully closed state, sets the cooling expansion valve 14b to a fully closed state, sets the cooling expansion valve 14c to a throttling state, and sets the bypass side flow control valve 14d to a throttling state. In addition, the control device 60 opens the high-pressure side on-off valve 22a and closes the low-pressure side on-off valve 22b.

[0174] Therefore, in the heat pump cycle 10 in the hot air heating mode, the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the indoor condenser 13, the high-pressure side passage 21b, the cooling expansion valve 14c in the throttle state, the sixth three-way joint 12f, the refrigerator 20, the accumulator 23, and the suction port of the compressor 11. At the same time, the refrigerant circuit is switched to one in which the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the bypass-side flow control valve 14d in the throttle state arranged in the bypass passage 21a, the sixth three-way joint 12f, the refrigerator 20, the accumulator 23, and the suction port of the compressor 11.

[0175] The control device 60 controls the rotation speed of the compressor 11 so that the cooling machine side refrigerant pressure Pc approaches the preset hot air heating target low pressure PSO1. The hot air heating target low pressure PSO1 is set so that the refrigerant evaporation temperature of the low pressure side refrigerant in the cooling machine 20 is higher than the outdoor air temperature Tam.

[0176] Here, controlling the chiller-side refrigerant pressure Pc corresponding to the pressure of the refrigerant sucked into the compressor 11 to a nearly constant pressure is effective in stabilizing the discharge flow rate Gr (mass flow rate) of the compressor 11. The reason is that by setting the refrigerant sucked into the compressor 11 to a saturated gas-phase refrigerant at a constant pressure, the density of the sucked refrigerant can be made constant. Therefore, it is easy to stabilize the discharge flow rate Gr of the compressor 11 at the same rotation speed.

[0177] In addition, the control device 60 controls the throttling opening of the cooling expansion valve 14c so that the refrigerant on the outlet side of the chiller 20 approaches the saturated gas phase refrigerant, that is, the superheat SHC of the refrigerant on the outlet side of the chiller 20 approaches 0° C. The superheat SHC of the refrigerant on the outlet side of the chiller 20 can be estimated based on the chiller side refrigerant temperature Tc and the chiller side refrigerant pressure Pc detected by the chiller side refrigerant temperature and pressure sensor 62e.

[0178] The control device 60 controls the throttling opening of the bypass flow regulating valve 14d so that the high and low pressure difference ΔP of the cycle approaches the target high and low pressure difference ΔPO1 for the hot gas heating mode. The high and low pressure difference ΔP is a value obtained by subtracting the chiller side refrigerant pressure Pc from the discharge refrigerant pressure Pd.

[0179] The target high-low pressure difference ΔPO1 for the hot air heating mode is determined based on the target outlet temperature TAO and with reference to a control map pre-stored in the control device 60. In the control map for the hot air heating mode, the target high-low pressure difference ΔPO1 is determined to be enlarged as the target outlet temperature TAO rises so that the compression workload of the compressor 11 becomes suitable for heating the heat of the supply air.

[0180] Furthermore, in the low-temperature side heat medium circuit 40 in the hot gas heating mode, the control device 60 stops the low-temperature side pump 41 .

[0181] In the indoor air conditioning unit 50 in the hot air heating mode, the control device 60 controls the rotation speed of the indoor blower 52, the opening degree of the air mix door 54, etc., similarly to the cooling mode alone. The control device 60 also appropriately controls the operation of other control target devices.

[0182] Therefore, in the heat pump cycle 10 in the hot air heating mode, the flow of the refrigerant discharged from the compressor 11 is branched by the first three-way joint 12a. The refrigerant on one side branched by the first three-way joint 12a flows into the indoor condenser 13. The refrigerant flowing into the indoor condenser 13 dissipates heat to the supply air, thereby reducing enthalpy. As a result, the supply air is heated.

[0183] The refrigerant flowing out of the indoor condenser 13 flows into the cooling expansion valve 14c through the high-pressure side passage 21b and is decompressed. The refrigerant with low enthalpy after being decompressed in the cooling expansion valve 14c flows into the other inlet of the sixth three-way joint 12f.

[0184] In addition, the other refrigerant branched by the first three-way joint 12a flows into the bypass passage 21a. The refrigerant flowing into the bypass passage 21a is flow-regulated by the bypass-side flow control valve 14d and decompressed. The refrigerant with a high enthalpy after being decompressed by the bypass-side flow control valve 14d flows into one inlet of the sixth three-way joint 12f.

[0185] In the sixth three-way joint 12f, the flow of the refrigerant flowing out of the cooling expansion valve 14c merges with the flow of the refrigerant flowing out of the bypass side flow control valve 14d and mixes. The refrigerant flowing out of the sixth three-way joint 12f flows into the refrigerator 20 and is further homogeneously mixed. The refrigerant flowing out of the refrigerant passage of the refrigerator 20 flows into the accumulator 23. The gas-phase refrigerant separated in the accumulator 23 is sucked into the compressor 11 and compressed again.

[0186] In the hot air heating mode, the interior air conditioning unit 50 heats the interior of the vehicle by blowing the supply air whose temperature has been adjusted into the vehicle interior, similarly to the outdoor air heat absorption heating mode alone.

[0187] Here, the hot air heating mode is executed when the outside air temperature Tam becomes an extremely low temperature. Therefore, when the refrigerant flowing out of the indoor condenser 13 flows into the outside air heat exchanger 15, the refrigerant may dissipate heat to the outside air in the outside air heat exchanger 15. If the refrigerant dissipates heat to the outside air in the outside air heat exchanger 15, the amount of heat dissipated by the refrigerant to the supply air in the indoor condenser 13 decreases, and the heating capacity of the supply air decreases.

[0188] In contrast, in the hot air heating mode, the refrigerant circuit is switched so that the refrigerant flowing out of the indoor condenser 13 does not flow into the outdoor air heat exchanger 15 , thereby suppressing the refrigerant from releasing heat to the outdoor air in the outdoor air heat exchanger 15 .

[0189] Furthermore, in the hot air heating mode, the throttling opening of the cooling expansion valve 14c is controlled so that the refrigerant at the outlet side of the cold machine 20 approaches the saturated gas phase refrigerant. Thus, even if the refrigerant discharge capacity of the compressor 11 is increased and the amount of heat dissipated from the refrigerant to the supply air in the indoor condenser 13 is increased, the cycle can be balanced.

[0190] Therefore, in the hot air heating mode, even if the outside air temperature Tam becomes extremely low, the heat generated by the operation of the compressor 11 can be effectively used to heat the supply air, thereby achieving heating of the vehicle interior.

[0191] As described above, in the vehicle air conditioning device 1 of the present embodiment, by switching the operation mode, it is possible to perform comfortable air conditioning in the vehicle interior and appropriate temperature adjustment of the battery 70 as the vehicle-mounted equipment.

[0192] However, in the above-mentioned outdoor air heat absorption heating mode, the refrigerant absorbs heat of outdoor air in the outdoor air heat exchanger 15. Therefore, when the outdoor air temperature Tam is low (0°C or lower), frost may form on the outdoor air heat exchanger 15 if the outdoor air heat absorption heating mode is executed.

[0193] If frost forms on the outside air heat exchanger 15, the outside air passage of the outside air heat exchanger 15 will be blocked by the frost, thereby reducing the heat exchange performance of the outside air heat exchanger 15. As a result, the refrigerant in the outside air heat exchanger 15 cannot fully absorb the heat of the outside air, and the heating capacity of the supply air in the indoor condenser 13 will be reduced.

[0194] Therefore, in the vehicle air conditioning device 1 of the present embodiment, when frost is generated on the outside air heat exchanger 15, a defrosting mode operation is performed to remove the frost attached to the outside air heat exchanger 15. Furthermore, in order to quickly and efficiently complete the defrosting of the outside air heat exchanger 15, the vehicle air conditioning device 1 switches between various defrosting modes. The switching of the defrosting mode is performed by executing Figure 4 The control flow shown is carried out.

[0195] Figure 4 The control flow shown is a sub-routine that is called at every predetermined period when a heating mode (in the present embodiment, an outdoor air absorption heating mode) is selected in the main flow of the control program. Figure 4 Each control step in the described flowchart is a function realization unit included in the control device 60 .

[0196] First, in Figure 4 In step S1, it is determined whether frost has occurred on the outdoor air heat exchanger 15. In step S1, when a preset frost condition is satisfied, it is determined that frost has occurred on the outdoor air heat exchanger 15. The frost condition of this embodiment is satisfied when the time during which the outdoor air side refrigerant temperature T2 detected by the outdoor air side refrigerant temperature and pressure sensor 62c becomes lower than a preset frost determination temperature KTf1 becomes longer than a preset frost determination time KTmf1.

[0197] In step S1, when it is determined that frost has occurred on the outdoor air heat exchanger 15, the process proceeds to step S2. In step S1, when it is determined that frost has not occurred on the outdoor air heat exchanger 15, the process returns to the main flow.

[0198] In step S2, it is determined whether the refrigerant in the cold machine 20 can absorb sufficient heat for defrosting from the battery 70 via the low-temperature side heat medium. Here, sufficient heat for defrosting refers to heat sufficient to complete the defrosting of the outdoor air heat exchanger 15. In step S2, specifically, it is determined whether the low-temperature side heat medium temperature TWL detected by the low-temperature side heat medium temperature sensor 63b is higher than the first reference heat medium temperature KTWL1 set in advance.

[0199] In step S2, when it is determined that low temperature side heat medium temperature TWL is equal to or higher than first reference heat medium temperature KTWL1, it is determined that the refrigerant can absorb sufficient defrosting heat from battery 70, and the process proceeds to step S4. In step S4, the heat absorption defrosting mode is executed, and the process proceeds to step S7.

[0200] If it is determined in step S2 that low-temperature-side heat medium temperature TWL is not equal to or higher than first reference heat medium temperature KTWL1, it is determined that the refrigerant cannot absorb sufficient defrosting heat from battery 70, and the process proceeds to step S3.

[0201] In step S3, it is determined whether the refrigerant in the cold machine 20 can absorb the defrosting heat from the battery 70 via the low-temperature side heat medium. In step S3, specifically, it is determined whether the low-temperature side heat medium temperature TWL is equal to or higher than a preset second reference heat medium temperature KTWL2. The second reference heat medium temperature KTWL2 is set to a value lower than the first reference heat medium temperature KTWL1.

[0202] In step S3, when it is determined that the low temperature side heat medium temperature TWL is equal to or higher than the second reference heat medium temperature KTWL2, it is determined that the defrosting heat is not sufficient, but the refrigerant can absorb the defrosting heat from the battery 70, and the process proceeds to step S5. In step S5, the heat absorption hot gas defrosting mode is executed, and the process proceeds to step S7.

[0203] If it is determined in step S3 that the low temperature side heat medium temperature TWL is not equal to or higher than the second reference heat medium temperature KTWL2, it is determined that the refrigerant cannot absorb defrosting heat from the battery 70, and the process proceeds to step S6. In step S6, the hot gas defrost mode is executed, and the process proceeds to step S7.

[0204] In step S7, it is determined whether the defrosting of the outdoor air heat exchanger 15 is completed. In step S7, when the preset termination condition is satisfied, it is determined that the defrosting of the outdoor air heat exchanger 15 is completed. The termination condition of this embodiment is satisfied when the time during which the outdoor air side refrigerant temperature T2 becomes higher than the preset termination determination temperature KTf2 becomes higher than the preset termination determination time KTmf2.

[0205] In step S7, when it is determined that the defrosting of the outdoor air heat exchanger 15 is completed, the process returns to the main flow. In step S7, when it is determined that the defrosting of the outdoor air heat exchanger 15 is not completed, the process returns to step S2. Each defrosting mode will be described below.

[0206] (e-1) Endothermic defrosting mode

[0207] First, the endothermic defrost mode executed in step S4 is described. The endothermic defrost mode includes a single endothermic defrost mode in which the outdoor air heat exchanger 15 is defrosted without heating the vehicle interior, and a heating endothermic defrost mode in which the outdoor air heat exchanger 15 is defrosted while heating the vehicle interior.

[0208] In the control routine of the present embodiment, when the heating switch of the operation panel 69 is turned on during the defrost mode, the heating-defrost mode is executed in which the vehicle interior is heated and the outdoor air heat exchanger 15 is defrosted.

[0209] (e-1-1) Single heat absorption defrosting mode

[0210] In the heat pump cycle 10 in the single heat absorption defrosting mode, the control device 60 sets the heating expansion valve 14a to a fully open state, sets the cooling expansion valve 14b to a fully closed state, sets the cooling expansion valve 14c to a throttling state, and sets the bypass side flow control valve 14d to a fully closed state. In addition, the control device 60 closes the high-pressure side on-off valve 22a and closes the low-pressure side on-off valve 22b.

[0211] Therefore, in the heat pump cycle 10 in the single heat absorption defrost mode, if Figure 5 As shown by the solid arrow, the refrigerant circuit is switched to one in which the refrigerant discharged from the compressor 11 circulates in the order of the indoor condenser 13, the heating expansion valve 14a which is in a fully open state, the outdoor air heat exchanger 15, the cooling expansion valve 14c which is in a throttling state, the cold machine 20, the liquid storage tank 23, and the suction port of the compressor 11.

[0212] Furthermore, the control device 60 controls the rotation speed of the compressor 11 so that the outside air-side refrigerant pressure P2 detected by the outside air-side refrigerant temperature and pressure sensor 62c approaches a preset reference defrosting pressure KPdf.

[0213] The reference defrost pressure KPdf is set so that the temperature of the refrigerant flowing into the outdoor air heat exchanger 15 becomes the reference defrost temperature KTdf. The reference defrost temperature KTdf is set so that the outdoor air side refrigerant pressure P2 does not rise unnecessarily and the defrosting of the outdoor air heat exchanger 15 can be completed quickly. Therefore, the control device 60 controls the rotation speed of the compressor 11 so that the temperature of the refrigerant flowing into the outdoor air heat exchanger 15 approaches the reference defrost temperature KTdf.

[0214] In addition, in the low temperature side heat medium circuit 40 in the heat absorption defrosting mode alone, the control device 60 operates the low temperature side pump 41 in the same manner as in the cooling refrigeration mode. Therefore, in the low temperature side heat medium circuit 40 in the heat absorption defrosting mode alone, as in the cooling refrigeration mode, Figure 5 As shown by the dotted arrows, the low-temperature side heat medium pumped by pressure from the low-temperature side pump 41 circulates.

[0215] In the indoor air conditioning unit 50 in the single heat absorption defrosting mode, the control device 60 stops the indoor blower 52. In addition, the control device 60 displaces the air mix door 54 to close the air passage on the indoor condenser 13 side. Furthermore, the control device 60 appropriately controls the operation of other control target devices.

[0216] Therefore, in the heat pump cycle 10 in the single heat absorption defrosting mode, the discharged refrigerant discharged from the compressor 11 flows into the indoor condenser 13 via the first three-way joint 12a. In the single heat absorption defrosting mode, the indoor blower 52 is stopped, and the air mixing door 54 closes the air passage on the indoor condenser 13 side, so the refrigerant flowing into the indoor condenser 13 does not dissipate heat to the supply air and flows out from the indoor condenser 13.

[0217] The refrigerant flowing out of the indoor condenser 13 flows into the outdoor air heat exchanger 15 through the heating expansion valve 14a which is in a fully opened state. When the refrigerant flowing into the outdoor air heat exchanger 15 flows through the outdoor air heat exchanger 15, it dissipates heat to the frost attached to the outdoor air heat exchanger 15 and condenses. As a result, the frost attached to the outdoor air heat exchanger 15 melts, and the outdoor air heat exchanger 15 is defrosted.

[0218] The refrigerant flowing out of the outdoor air heat exchanger 15 flows into the cooling expansion valve 14c and is decompressed. The low-pressure side refrigerant decompressed in the cooling expansion valve 14c flows into the refrigerant passage of the cold machine 20. The low-pressure side refrigerant flowing into the cold machine 20 absorbs the defrosting heat from the low-temperature side heat medium flowing in the heat medium passage and evaporates.

[0219] The refrigerant flowing out of the refrigerator 20 flows into the accumulator 23 to be separated into gas and liquid. The gas-phase refrigerant flowing out of the accumulator 23 is sucked into the compressor 11 to be compressed again.

[0220] In the low-temperature side heat medium circuit 40 in the single heat absorption defrosting mode, the low-temperature side heat medium pumped by the low-temperature side pump 41 flows into the heat medium passage of the refrigerator 20. The low-temperature side heat medium flowing into the refrigerator 20 absorbs the defrosting heat from the low-temperature side refrigerant flowing in the refrigerant passage and is cooled.

[0221] The low-temperature side heat medium flowing out of the heat medium passage of the cold machine 20 flows into the cooling water passage 70a of the battery 70. The low-temperature side heat medium flowing into the cooling water passage 70a of the battery 70 absorbs the defrosting heat generated by the battery 70. The low-temperature side heat medium flowing out of the cooling water passage 70a of the battery 70 is sucked into the low-temperature side pump 41 and is pressure-sent to the heat medium passage of the cold machine 20 again.

[0222] (e-1-2) Heating and defrosting mode

[0223] In the heat pump cycle 10 in the heating heat absorption defrosting mode, the control device 60 sets the heating expansion valve 14a to the throttling state, sets the cooling expansion valve 14b to the fully closed state, sets the cooling expansion valve 14c to the throttling state, and sets the bypass side flow control valve 14d to the fully closed state. In addition, the control device 60 closes the high-pressure side on-off valve 22a and closes the low-pressure side on-off valve 22b.

[0224] Therefore, in the heat pump cycle 10 in the heating endothermic defrosting mode, Figure 5 As shown by the solid arrow, the refrigerant circuit is switched to one in which the refrigerant discharged from the compressor 11 circulates in the order of the indoor condenser 13, the heating expansion valve 14a which is in a throttling state, the outdoor air heat exchanger 15, the cooling expansion valve 14c which is in a throttling state, the cold machine 20, the liquid storage tank 23, and the suction port of the compressor 11.

[0225] Then, the control device 60 controls the rotation speed of the compressor 11 so that the discharge refrigerant pressure Pd approaches the heating target pressure PDO, similarly to the outdoor air heat absorption heating mode.

[0226] Furthermore, the control device 60 controls the throttle opening degree of the heating expansion valve 14a so that the outdoor refrigerant pressure P2 approaches the reference defrosting pressure KPdf.

[0227] In addition, in the low temperature side heat medium circuit 40 in the heating heat absorption defrosting mode, the control device 60 operates the low temperature side pump 41 in the same manner as in the cooling refrigeration mode. Figure 5 As shown by the dotted arrows, the low-temperature side heat medium pumped by pressure from the low-temperature side pump 41 circulates.

[0228] In the indoor air conditioning unit 50 in the heating heat absorption defrosting mode, the control device 60 controls the rotation speed of the indoor blower 52, the opening degree of the air mix door 54, etc., similarly to the cooling mode alone. The control device 60 also appropriately controls the operation of other control target devices.

[0229] Therefore, in the heat pump cycle 10 in the heating heat absorption defrosting mode, the refrigerant discharged from the compressor 11 flows into the indoor condenser 13 via the first three-way joint 12a. The refrigerant flowing into the indoor condenser 13 dissipates heat to the supply air according to the opening degree of the air mix door 54 and condenses.

[0230] The refrigerant flowing out of the indoor condenser 13 is decompressed in the heating expansion valve 14a. As a result, the outdoor refrigerant pressure P2 approaches the reference defrosting pressure KPdf. That is, the temperature of the refrigerant flowing into the outdoor heat exchange unit 15 approaches the reference defrosting temperature KTdf.

[0231] The refrigerant decompressed by the heating expansion valve 14a flows into the outdoor air heat exchanger 15. When the refrigerant flowing into the outdoor air heat exchanger 15 flows through the outdoor air heat exchanger 15, it dissipates heat to the frost attached to the outdoor air heat exchanger 15 and condenses. As a result, the frost attached to the outdoor air heat exchanger 15 melts, thereby achieving defrosting of the outdoor air heat exchanger 15. The operation of the heat pump cycle 10 thereafter is the same as that in the single heat absorption defrosting mode.

[0232] In the low-temperature side heat medium circuit 40 in the heating heat absorption defrosting mode, similarly to the single heat absorption defrosting mode, the low-temperature side heat medium flowing into the cooling water passage 70a of the battery 70 absorbs the defrosting heat generated by the battery 70. Furthermore, the low-temperature side heat medium flowing into the refrigerator 20 absorbs the defrosting heat by the low-temperature side refrigerant flowing through the refrigerant passage.

[0233] In the heating heat absorption defrosting mode, the interior air conditioning unit 50 heats the interior of the vehicle by blowing the supply air whose temperature has been adjusted into the vehicle interior, similarly to the outside air heat absorption heating mode alone.

[0234] Here, in the heating heat absorption defrosting mode, the defrosting heat absorbed by the refrigerant in the refrigerator 20 is dissipated to the supply air in addition to the frost attached to the outdoor air heat exchanger 15. Therefore, in the heating heat absorption defrosting mode, the low temperature side heat medium temperature TWL is easier to decrease than in the heat absorption defrosting mode alone. Therefore, the heating heat absorption defrosting mode is easier to shift to the heat absorption hot gas defrosting mode than in the heat absorption defrosting mode alone.

[0235] (e-2) Heat absorption hot gas defrosting mode

[0236] Next, the heat absorption hot gas defrost mode executed in step S5 is described. The heat absorption hot gas defrost mode includes a heat absorption hot gas defrost mode alone in which the outdoor air heat exchanger 15 is defrosted without heating the vehicle interior, and a heating heat absorption hot gas defrost mode in which the outdoor air heat exchanger 15 is defrosted while heating the vehicle interior.

[0237] (e-2-1) Single heat absorption hot gas defrosting mode

[0238] In the heat pump cycle 10 in the heat absorption hot gas defrosting mode alone, the control device 60 sets the heating expansion valve 14a to a fully open state or a throttle state, sets the cooling expansion valve 14b to a fully closed state, sets the cooling expansion valve 14c to a throttle state, and sets the bypass side flow control valve 14d to a throttle state. In addition, the control device 60 closes the high-pressure side on-off valve 22a and closes the low-pressure side on-off valve 22b.

[0239] Therefore, in the heat pump cycle 10 in the single heat absorption hot gas defrost mode, if Figure 6As shown by the solid arrows, the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the indoor condenser 13, the heating expansion valve 14a in the fully open state or the throttled state, the outdoor air heat exchanger 15, the cooling expansion valve 14c in the throttled state, the sixth three-way joint 12f, the refrigerator 20, the accumulator 23, and the suction port of the compressor 11. At the same time, the refrigerant circuit is switched to one in which the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the bypass-side flow control valve 14d in the throttled state arranged in the bypass passage 21a, the sixth three-way joint 12f, the refrigerator 20, the accumulator 23, and the suction port of the compressor 11.

[0240] Furthermore, the control device 60 controls the refrigerant discharge capacity of the compressor 11 so that the refrigerant pressure Pc on the chiller side approaches the preset target low pressure PSO2 for heat absorption hot gas defrosting. The target low pressure PSO2 for heat absorption hot gas defrosting is set in such a way that the refrigerant evaporation temperature of the low-pressure side refrigerant in the chiller 20 becomes lower than the second reference heat medium temperature KTWL2.

[0241] In addition, the control device 60 controls the throttling opening of the heating expansion valve 14a in the same manner as in the heating heat absorption defrosting mode so that the outside air side refrigerant pressure P2 approaches the reference defrosting pressure KPdf. In addition, the control device 60 controls the throttling opening of the cooling expansion valve 14c in the same manner as in the hot air heating mode so that the refrigerant on the outlet side of the cold machine 20 approaches the saturated gas phase refrigerant.

[0242] In addition, the control device 60 controls the throttling opening of the bypass side flow control valve 14d so that the high and low pressure difference ΔP of the cycle approaches the target high and low pressure difference ΔPO2 for the heat absorption hot gas defrosting mode alone. The target high and low pressure difference ΔPO2 for the heat absorption hot gas defrosting mode alone is determined by referring to the control map pre-stored in the control device 60.

[0243] Here, the target high-low pressure difference ΔPO2 for the heat absorption hot gas defrosting mode is set in a manner that can quickly and efficiently complete the defrosting of the outdoor air heat exchanger 15. In other words, it is set in a manner that does not unnecessarily increase the refrigerant discharge capacity of the compressor 11. Therefore, the discharge refrigerant pressure Pd may become a value equal to the reference defrosting pressure KPdf. In this case, the heating expansion valve 14a becomes fully open.

[0244] In addition, in the low temperature side heat medium circuit 40 in the heat absorption hot gas defrosting mode alone, the control device 60 operates the low temperature side pump 41 in the same manner as in the cooling refrigeration mode. Therefore, in the low temperature side heat medium circuit 40 in the heat absorption hot gas defrosting mode alone, the heat absorption hot gas defrosting mode is controlled in the same manner as in the cooling refrigeration mode. Figure 6 As shown by the dotted arrows, the low-temperature side heat medium pumped by pressure from the low-temperature side pump 41 circulates.

[0245] In the indoor air conditioning unit 50 in the heat absorption hot gas defrosting mode alone, the control device 60 stops the indoor blower 52 and displaces the air mix door 54 to close the air passage on the indoor condenser 13 side, as in the heat absorption hot gas defrosting mode alone. The control device 60 also appropriately controls the operation of other control target devices.

[0246] Therefore, in the heat pump cycle 10 in the heat absorption hot gas defrosting mode alone, the state of the refrigerant is as follows: Figure 7 The Mollier Line diagram shows the change.

[0247] That is, the discharged refrigerant ( Figure 7 The flow of the refrigerant at point a7 of the indoor condenser 13 is branched by the first three-way joint 12a. The refrigerant on one side branched by the first three-way joint 12a flows into the indoor condenser 13. In the single heat absorption hot gas defrosting mode, the indoor blower 52 is stopped, and the air mixing door 54 closes the air passage on the indoor condenser 13 side, so the refrigerant flowing into the indoor condenser 13 does not dissipate heat to the supply air and flows out of the indoor condenser 13.

[0248] The refrigerant flowing out of the indoor condenser 13 is decompressed by the heating expansion valve 14a (from Figure 7 As a result, the outside air side refrigerant pressure P2 approaches the reference defrosting pressure KPdf. That is, the temperature of the refrigerant flowing into the outside air heat exchange unit 15 approaches the reference defrosting temperature KTdf.

[0249] The refrigerant decompressed by the heating expansion valve 14a flows into the outdoor air heat exchanger 15. When the refrigerant flowing into the outdoor air heat exchanger 15 flows through the outdoor air heat exchanger 15, it dissipates heat to the frost attached to the outdoor air heat exchanger 15 and condenses (from the outdoor air heat exchanger 15). Figure 7 Thus, the frost attached to the outside air heat exchanger 15 melts, thereby achieving defrosting of the outside air heat exchanger 15.

[0250] Here, as described above, in the heat absorption hot gas defrosting mode alone, the heating expansion valve 14a may be in a fully open state. In this case, the state of the refrigerant is as follows: Figure 7 The value changes as shown by the single-dot chain line.

[0251] The refrigerant flowing out of the outdoor air heat exchanger 15 flows into the cooling expansion valve 14c and is decompressed (from Figure 7 The low-pressure refrigerant decompressed in the cooling expansion valve 14c flows into the other inlet of the sixth three-way joint 12f.

[0252] The other refrigerant branched by the first three-way joint 12a flows into the bypass passage 21a. The refrigerant flowing into the bypass passage 21a is flow-regulated by the bypass-side flow-regulating valve 14d and is decompressed (from Figure 7 The refrigerant with high enthalpy that has been decompressed in the bypass-side flow control valve 14d flows into one inlet of the sixth three-way joint 12f.

[0253] In the sixth three-way joint 12f, the flow of the refrigerant flowing out of the cooling expansion valve 14c merges with the flow of the refrigerant flowing out of the bypass flow control valve 14d and mixes (from Figure 7 The refrigerant flowing out of the sixth three-way joint 12f flows into the refrigerator 20. The low-pressure side refrigerant flowing into the refrigerator 20 absorbs the defrosting heat from the low-temperature side heat medium flowing in the heat medium passage and evaporates (from Figure 7 f7 to g7).

[0254] The refrigerant flowing out of the refrigerator 20 flows into the accumulator 23 and is separated into gas and liquid. The gas-phase refrigerant flowing out of the accumulator 23 is sucked into the compressor 11 and compressed again (from Figure 7 from g7 to a7).

[0255] In the low-temperature side heat medium circuit 40 in the heat absorption hot gas defrosting mode alone, similarly to the heat absorption defrosting mode alone, the low-temperature side heat medium flowing into the cooling water passage 70a of the battery 70 absorbs the defrosting heat generated by the battery 70. Furthermore, the low-temperature side heat medium flowing into the refrigerator 20 absorbs the defrosting heat by the low-temperature side refrigerant flowing through the refrigerant passage.

[0256] (e-2-2) Heating and heat absorption hot gas defrosting mode

[0257] In the heat pump cycle 10 in the heating heat absorption hot gas defrosting mode, the control device 60 sets the heating expansion valve 14a to the throttling state, sets the cooling expansion valve 14b to the fully closed state, sets the cooling expansion valve 14c to the throttling state, and sets the bypass side flow control valve 14d to the throttling state. In addition, the control device 60 closes the high-pressure side on-off valve 22a and closes the low-pressure side on-off valve 22b.

[0258] Therefore, in the heat pump cycle 10 in the heating endothermic hot gas defrosting mode, as shown in FIG. Figure 6As shown by the solid arrows, the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the indoor condenser 13, the heating expansion valve 14a in the throttle state, the outdoor air heat exchanger 15, the cooling expansion valve 14c in the throttle state, the sixth three-way joint 12f, the refrigerator 20, the accumulator 23, and the suction port of the compressor 11. At the same time, the refrigerant circuit is switched to one in which the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the bypass-side flow control valve 14d in the throttle state arranged in the bypass passage 21a, the sixth three-way joint 12f, the refrigerator 20, the accumulator 23, and the suction port of the compressor 11.

[0259] Then, the control device 60 controls the refrigerant discharge capacity of the compressor 11 so that the cooling machine side refrigerant pressure Pc approaches the target low pressure PSO2 for the heat absorption hot gas defrosting, similarly to the heat absorption hot gas defrosting mode alone.

[0260] In addition, the control device 60 controls the throttling opening of the heating expansion valve 14a in the same manner as in the heating heat absorption defrosting mode so that the outside air side refrigerant pressure P2 approaches the reference defrosting pressure KPdf. In addition, the control device 60 controls the throttling opening of the cooling expansion valve 14c in the same manner as in the hot air heating mode so that the refrigerant on the outlet side of the cold machine 20 approaches the saturated gas phase refrigerant.

[0261] In addition, the control device 60 controls the throttling opening of the bypass side flow control valve 14d so that the high and low pressure difference ΔP of the cycle approaches the target high and low pressure difference ΔPO3 for the heating heat absorption hot gas defrosting mode. The target high and low pressure difference ΔPO3 for the heating heat absorption hot gas defrosting mode is determined by referring to the control map pre-stored in the control device 60.

[0262] Here, the target high-low pressure difference ΔPO3 for the heating heat absorption hot gas defrosting mode is set to achieve appropriate heating in the vehicle interior. In order to achieve appropriate heating in the vehicle interior, more heat is required than defrosting the outdoor air heat exchanger 15. Therefore, the target high-low pressure difference ΔPO3 for the heating heat absorption hot gas defrosting mode becomes a value greater than the target high-low pressure difference ΔPO2 for the single heat absorption hot gas defrosting mode.

[0263] In the low temperature side heat medium circuit 40 in the heating heat absorption hot gas defrosting mode, the control device 60 operates the low temperature side pump 41 in the same manner as in the cooling refrigeration mode. Figure 6 As shown by the dotted arrows, the low-temperature side heat medium pumped by pressure from the low-temperature side pump 41 circulates.

[0264] In the indoor air conditioning unit 50 in the heating heat absorption hot gas defrosting mode, the control device 60 controls the rotation speed of the indoor blower 52, the opening degree of the air mix door 54, etc., similarly to the cooling mode alone. The control device 60 also appropriately controls the operation of other control target devices.

[0265] Therefore, in the heat pump cycle 10 in the heating and heat absorption hot gas defrosting mode, the state of the refrigerant is as follows: Figure 8 The Mollier Line Chart shows that Figure 8 In the case of single heat absorption hot gas defrost mode, Figure 7 The Mollier diagram marks the state of the refrigerant in the same position in the cycle structure. Figure 7 The same symbols (letters) are used to represent the same figures, and only the numbers (numbers) are changed. This is also the case in the following Mollier diagrams.

[0266] That is, the discharged refrigerant ( Figure 8 The refrigerant flowing into the indoor condenser 13 exchanges heat with the supply air according to the opening degree of the air mixing door 54, and condenses (from Figure 8 As a result, the supply air is heated.

[0267] The refrigerant flowing out of the indoor condenser 13 is decompressed by the heating expansion valve 14a (from Figure 8 As a result, the outside air side refrigerant pressure P2 approaches the reference defrosting pressure KPdf. That is, the temperature of the refrigerant flowing into the outside air heat exchange unit 15 approaches the reference defrosting temperature KTdf.

[0268] The refrigerant decompressed by the heating expansion valve 14a flows into the outdoor air heat exchanger 15. When the refrigerant flowing into the outdoor air heat exchanger 15 flows through the outdoor air heat exchanger 15, it dissipates heat to the frost attached to the outdoor air heat exchanger 15 and condenses (from the outdoor air heat exchanger 15). Figure 8 Thus, the frost attached to the outside air heat exchanger 15 melts, thereby achieving defrosting of the outside air heat exchanger 15. The operation of the heat pump cycle 10 thereafter is the same as that in the single heat absorption hot gas defrosting mode.

[0269] In the low-temperature side heat medium circuit 40 in the heating heat absorption hot gas defrosting mode, similarly to the single heat absorption hot gas defrosting mode, the low-temperature side heat medium flowing into the cooling water passage 70a of the battery 70 absorbs the defrosting heat generated by the battery 70. Furthermore, the low-temperature side heat medium flowing into the refrigerator 20 absorbs the defrosting heat by the low-temperature side refrigerant flowing through the refrigerant passage.

[0270] In the heating heat absorption hot air defrosting mode, the interior air conditioning unit 50 heats the interior of the vehicle by blowing the supply air whose temperature has been adjusted into the vehicle interior, similarly to the outside air heat absorption heating mode alone.

[0271] Here, in the heating heat absorption hot gas defrost mode, the defrost heat absorbed by the refrigerant in the refrigerator 20 is dissipated to the supply air in addition to the frost attached to the outdoor air heat exchanger 15. Therefore, in the heating heat absorption hot gas defrost mode, the low temperature side heat medium temperature TWL is easier to decrease than in the heat absorption hot gas defrost mode alone. Therefore, the heating heat absorption hot gas defrost mode is easier to shift to the hot gas defrost mode than in the heat absorption hot gas defrost mode alone.

[0272] (e-3) Hot gas defrost mode

[0273] Next, the hot gas defrost mode executed in step S6 is described. The hot gas defrost mode includes a hot gas defrost mode alone in which the outdoor air heat exchanger 15 is defrosted without heating the vehicle interior, and a heating hot gas defrost mode in which the outdoor air heat exchanger 15 is defrosted while heating the vehicle interior.

[0274] (e-3-1) Hot gas defrost mode only

[0275] In the heat pump cycle 10 in the hot gas defrost mode alone, the control device 60 sets the heating expansion valve 14a to a fully open state or a throttle state, sets the cooling expansion valve 14b to a fully closed state, sets the cooling expansion valve 14c to a throttle state, and sets the bypass side flow control valve 14d to a throttle state. In addition, the control device 60 closes the high-pressure side on-off valve 22a and closes the low-pressure side on-off valve 22b.

[0276] Therefore, in the heat pump cycle 10 in the hot gas defrost mode alone, if Fig. 9 As shown by the solid arrows, the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the heating expansion valve 14a in the fully open state or the throttled state, the outdoor air heat exchanger 15, the cooling expansion valve 14c in the throttled state, the sixth three-way joint 12f, the refrigerator 20, the accumulator 23, and the suction port of the compressor 11. At the same time, the refrigerant circuit is switched to one in which the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the bypass-side flow control valve 14d in the throttled state arranged in the bypass passage 21a, the sixth three-way joint 12f, the refrigerator 20, the accumulator 23, and the suction port of the compressor 11.

[0277] The control device 60 controls the refrigerant discharge capacity of the compressor 11 so that the cooling machine side refrigerant pressure Pc approaches the preset hot gas defrosting target low pressure PSO3. The hot gas defrosting target low pressure PSO3 is set to a pressure higher than the heat absorption hot gas defrosting target low pressure PSO2.

[0278] In addition, the control device 60 controls the throttling opening of the heating expansion valve 14a in the same manner as in the heating heat absorption defrosting mode so that the outside air side refrigerant pressure P2 approaches the reference defrosting pressure KPdf. In addition, the control device 60 controls the throttling opening of the cooling expansion valve 14c in the same manner as in the hot air heating mode so that the refrigerant on the outlet side of the cold machine 20 approaches the saturated gas phase refrigerant.

[0279] The control device 60 controls the throttling opening of the bypass flow control valve 14d so that the high and low pressure difference ΔP of the cycle approaches the target high and low pressure difference ΔPO4 for the hot gas defrosting mode alone. The target high and low pressure difference ΔPO4 for the hot gas defrosting mode alone is determined by referring to a control map pre-stored in the control device 60.

[0280] Here, the target high-low pressure difference ΔPO4 for the hot gas defrost mode alone is set in such a way that the defrosting of the outdoor air heat exchanger 15 can be completed quickly and efficiently. In other words, it is set so as not to unnecessarily increase the refrigerant discharge capacity of the compressor 11. Therefore, the discharge refrigerant pressure Pd will also become a value equal to the reference defrost pressure KPdf. In this case, the heating expansion valve 14a is in a fully open state.

[0281] Furthermore, in the low-temperature side heat medium circuit 40 in the hot gas alone defrosting mode, the control device 60 stops the low-temperature side pump 41 .

[0282] In the indoor air conditioning unit 50 in the hot air defrosting mode alone, the control device 60 stops the indoor blower 52 and displaces the air mix door 54 to close the air passage on the indoor condenser 13 side, similarly to the heat absorption defrosting mode alone. The control device 60 also appropriately controls the operation of other control target devices.

[0283] Therefore, in the heat pump cycle 10 in the hot gas defrost mode alone, the state of the refrigerant is as follows: Fig.10 The Mollier Line diagram shows the change.

[0284] That is, the discharged refrigerant ( Fig.10The refrigerant flowing into the indoor condenser 13 is branched by the first three-way joint 12a. The refrigerant on one side branched by the first three-way joint 12a flows into the indoor condenser 13. In the single hot air defrosting mode, the indoor blower 52 is stopped, and the air mixing door 54 closes the air passage on the indoor condenser 13 side, so the refrigerant flowing into the indoor condenser 13 does not dissipate heat to the supply air and flows out of the indoor condenser 13.

[0285] The refrigerant flowing out of the indoor condenser 13 is decompressed by the heating expansion valve 14a (from Fig.10 As a result, the outside air side refrigerant pressure P2 approaches the reference defrosting pressure KPdf. That is, the temperature of the refrigerant flowing into the outside air heat exchange unit 15 approaches the reference defrosting temperature KTdf.

[0286] The refrigerant decompressed by the heating expansion valve 14a flows into the outdoor air heat exchanger 15. When the refrigerant flowing into the outdoor air heat exchanger 15 flows through the outdoor air heat exchanger 15, it dissipates heat to the frost attached to the outdoor air heat exchanger 15 and condenses (from the outdoor air heat exchanger 15). Fig.10 Thus, the frost attached to the outside air heat exchanger 15 melts, thereby achieving defrosting of the outside air heat exchanger 15.

[0287] Here, as described above, in the hot gas defrosting mode alone, the heating expansion valve 14a may be in a fully open state, similarly to the heat absorption hot gas defrosting mode alone. In this case, the state of the refrigerant is as follows: Fig.10 The single-dot dash line changes.

[0288] The refrigerant flowing out of the outdoor air heat exchanger 15 flows into the cooling expansion valve 14c and is decompressed (from Fig.10 The low-pressure refrigerant decompressed in the cooling expansion valve 14c flows into the other inlet of the sixth three-way joint 12f.

[0289] The other refrigerant branched by the first three-way joint 12a flows into the bypass passage 21a. The refrigerant flowing into the bypass passage 21a is flow-regulated by the bypass-side flow-regulating valve 14d and is decompressed (from Fig.10 The refrigerant with high enthalpy that has been decompressed in the bypass-side flow control valve 14d flows into one inlet of the sixth three-way joint 12f.

[0290] In the sixth three-way joint 12f, the flow of the refrigerant flowing out of the cooling expansion valve 14c merges with the flow of the refrigerant flowing out of the bypass flow control valve 14d and mixes (from Fig.10 The refrigerant flowing out from the sixth three-way joint 12f flows into the refrigerator 20, and is further homogeneously mixed.

[0291] The refrigerant flowing out of the refrigerator 20 flows into the accumulator 23 and is separated into gas and liquid. The gas-phase refrigerant flowing out of the accumulator 23 is sucked into the compressor 11 and compressed again (from Fig.10 from point g10 to point a10).

[0292] (e-3-2) Heating hot air defrost mode

[0293] In the heat pump cycle 10 in the heating hot gas defrost mode, the control device 60 sets the heating expansion valve 14a to the throttling state, sets the cooling expansion valve 14b to the fully closed state, sets the cooling expansion valve 14c to the throttling state, and sets the bypass side flow control valve 14d to the throttling state. In addition, the control device 60 closes the high-pressure side on-off valve 22a and closes the low-pressure side on-off valve 22b.

[0294] Therefore, in the heat pump cycle 10 in the heating hot gas defrost mode, if Fig. 9 As shown by the solid arrows, the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the heating expansion valve 14a in the throttle state, the outdoor air heat exchanger 15, the cooling expansion valve 14c in the throttle state, the sixth three-way joint 12f, the refrigerator 20, the accumulator 23, and the suction port of the compressor 11. At the same time, the refrigerant circuit is switched to one in which the refrigerant discharged from the compressor 11 circulates in the order of the first three-way joint 12a, the bypass-side flow control valve 14d in the throttle state arranged in the bypass passage 21a, the sixth three-way joint 12f, the refrigerator 20, the accumulator 23, and the suction port of the compressor 11.

[0295] Then, the control device 60 controls the refrigerant discharge capacity of the compressor 11 so that the cooling machine-side refrigerant pressure Pc approaches the target low pressure PSO3 for hot gas defrosting, similarly to the hot gas defrosting mode.

[0296] In addition, the control device 60 controls the throttling opening of the heating expansion valve 14a in the same manner as in the heating heat absorption defrosting mode so that the outside air side refrigerant pressure P2 approaches the reference defrosting pressure KPdf. In addition, the control device 60 controls the throttling opening of the cooling expansion valve 14c in the same manner as in the hot air heating mode so that the refrigerant on the outlet side of the cold machine 20 approaches the saturated gas phase refrigerant.

[0297] The control device 60 controls the throttling opening of the bypass flow regulating valve 14d so that the high and low pressure difference ΔP of the cycle approaches the target high and low pressure difference ΔPO5 for the heating hot gas defrosting mode. The target high and low pressure difference ΔPO5 for the heating hot gas defrosting mode is determined by referring to the control map pre-stored in the control device 60.

[0298] Here, the target high-low pressure difference ΔPO5 for the heating hot air defrost mode is set to achieve appropriate heating in the vehicle interior. In order to achieve appropriate heating in the vehicle interior, more heat is required than for defrosting the outdoor air heat exchanger 15. Therefore, the target high-low pressure difference ΔPO5 for the heating hot air defrost mode becomes a value greater than the target high-low pressure difference ΔPO4 for the hot air defrost mode alone.

[0299] Furthermore, in the low-temperature side heat medium circuit 40 in the heating hot gas defrost mode, the control device 60 stops the low-temperature side pump 41 .

[0300] In the indoor air conditioning unit 50 in the heating hot air defrost mode, the control device 60 controls the rotation speed of the indoor blower 52, the opening degree of the air mix door 54, etc., similarly to the cooling mode alone. The control device 60 also appropriately controls the operation of other control target devices.

[0301] Therefore, in the heat pump cycle 10 in the heating hot gas defrost mode, the state of the refrigerant is as follows: Fig.11 The Mollier Line diagram shows the change.

[0302] That is, the discharged refrigerant ( Fig.11 The refrigerant flowing into the indoor condenser 13 exchanges heat with the supply air according to the opening degree of the air mixing door 54, and condenses (from Fig.11 As a result, the supply air is heated.

[0303] The refrigerant flowing out of the indoor condenser 13 is decompressed by the heating expansion valve 14a (from Fig.11 Thus, the outside air side refrigerant pressure P2 approaches the reference defrosting pressure KPdf. That is, the temperature of the refrigerant flowing into the outside air heat exchange unit 15 approaches the reference defrosting temperature KTdf.

[0304] The refrigerant decompressed by the heating expansion valve 14a flows into the outdoor air heat exchanger 15. When the refrigerant flowing into the outdoor air heat exchanger 15 flows through the outdoor air heat exchanger 15, it dissipates heat to the frost attached to the outdoor air heat exchanger 15 and condenses (from the outdoor air heat exchanger 15). Fig.11 Thus, the frost attached to the outside air heat exchanger 15 melts, thereby achieving defrosting of the outside air heat exchanger 15. The operation of the heat pump cycle 10 thereafter is the same as that in the hot gas defrosting mode alone.

[0305] In the heating hot air defrost mode, the interior air conditioning unit 50 heats the interior of the vehicle by blowing the supply air whose temperature has been adjusted into the vehicle interior, similarly to the outside air heat absorption heating mode alone.

[0306] As described above, in the vehicle air conditioning device 1 of the present embodiment, by switching various defrosting modes, it is possible to quickly and efficiently complete defrosting of the outdoor air heat exchanger 15 .

[0307] More specifically, in the (e-2) heat absorption hot gas defrosting mode and the (e-3) hot gas defrosting mode of the present embodiment, the refrigerant decompressed in the cooling expansion valve 14c is mixed with the refrigerant flowing out of the bypass-side flow control valve 14d and sucked into the compressor 11. That is, the refrigerant decompressed in the cooling expansion valve 14c is mixed with the refrigerant having a higher enthalpy, so that the cycle is balanced.

[0308] Therefore, in the (e-2) heat absorption hot gas defrosting mode and the (e-3) hot gas defrosting mode, the refrigerant at the outlet side of the outdoor air heat exchanger 15 can be made into a refrigerant with a lower enthalpy, and the heat dissipation amount of the refrigerant in the outdoor air heat exchanger 15 can be increased. Fig.10 As shown from point c10 to point d10, the heat dissipation can be increased.

[0309] As a result, the amount of heat dissipated from the refrigerant flowing through the outdoor air heat exchanger 15 to the frost attached to the outdoor air heat exchanger 15 can be increased, and defrosting of the outdoor air heat exchanger 15 can be completed quickly.

[0310] Furthermore, in the hot gas defrost mode (e-3), the target low pressure PSO3 for hot gas defrost is set to a pressure higher than the target low pressure PSO2 for heat absorption hot gas defrost. Therefore, the compressor 11 can suck in a refrigerant with a high density. Furthermore, the discharge flow rate Gr of the compressor 11 at the same rotation speed can be increased.

[0311] As a result, in the hot air defrost mode (e-3), the outdoor air heat exchanger 15 can be defrosted quickly without using the defrosting heat generated by the battery 70. That is, the outdoor air heat exchanger 15 can be defrosted quickly without requiring an endothermic source for generating defrosting heat.

[0312] In addition, in the defrost mode of the present embodiment, Figure 4 As described in steps S2 and S3 of the present invention, when the refrigerant in the refrigerator 20 is able to absorb the defrosting heat generated by the battery 70, the refrigerant in the refrigerator 20 absorbs the defrosting heat.

[0313] Therefore, in the (e-2) heat absorption hot gas defrosting mode, even if the compression workload of the compressor 11 is reduced compared to the (e-3) hot gas defrosting mode, the defrosting of the outdoor air heat exchanger 15 can be completed quickly. As a result, in the (e-2) heat absorption hot gas defrosting mode, the defrosting of the outdoor air heat exchanger 15 can be completed more efficiently and quickly than in the (e-3) hot gas defrosting mode.

[0314] Furthermore, in the defrost mode of the present embodiment, Figure 4 As described in step S2 of the embodiment, when the refrigerant in the refrigerator 20 can absorb enough heat for defrosting, the mode can be switched to the (e-1) heat absorption defrosting mode. In the (e-1) heat absorption defrosting mode, the compression work of the compressor 11 and the heat for defrosting can be used to defrost the outdoor air heat exchanger 15 using the condensation heat.

[0315] Therefore, in the (e-1) heat absorption defrosting mode, the defrosting of the outdoor air heat exchanger 15 can be completed more efficiently and quickly than in the (e-2) heat absorption hot gas defrosting mode and the (e-3) hot gas defrosting mode.

[0316] Furthermore, in the defrost mode of the present embodiment, Figure 4 As described in steps S2 and S3 of the present invention, the low temperature side heat medium temperature TWL is used to determine whether the refrigerant in the refrigerator 20 can absorb the defrosting heat. In this way, it is possible to easily determine whether the refrigerant in the refrigerator 20 can absorb the defrosting heat.

[0317] In addition, the vehicle air conditioning device 1 of this embodiment is provided with a heating expansion valve 14a as an upstream pressure reducing unit. Therefore, in the defrosting mode, the refrigerant decompressed by the heating expansion valve 14a can flow into the outdoor air heat exchanger 15 to dissipate heat. As a result, the temperature of the refrigerant flowing into the outdoor air heat exchanger 15 can be adjusted without excessively reducing the rotation speed of the compressor 11, thereby stabilizing the operating state of the compressor 11.

[0318] Furthermore, in the defrosting mode of the present embodiment, the throttling opening of the heating expansion valve 14a is controlled so that the temperature of the refrigerant flowing into the outdoor heat exchanger 15 approaches the reference defrosting temperature KTdf. Thus, the pressure of the refrigerant flowing into the outdoor heat exchanger 15 does not increase unnecessarily, and the defrosting of the outdoor heat exchanger 15 can be completed quickly.

[0319] In addition, the vehicle air conditioning device 1 of the present embodiment includes an indoor condenser 13 as a heating unit. Therefore, as described in the (e-1-2) heating heat absorption defrosting mode, the (e-2-2) heating heat absorption hot gas defrosting mode, and the (e-3-2) heating hot gas defrosting mode, the interior of the vehicle can be heated while the outdoor air heat exchanger 15 is defrosted.

[0320] The present invention is not limited to the above-described embodiment, and various modifications may be made as described below without departing from the gist of the present invention.

[0321] In the above-mentioned embodiment, an example of applying the heat pump circulation device involved in the present invention to a vehicle air conditioning device is described, but the application object of the heat pump circulation device is not limited to the vehicle air conditioning device. For example, it can also be applied to an air conditioning device that does not adjust the temperature of the heat generating device and only performs air conditioning of the air conditioning target space. For example, as a heating object, it can also be applied to a hot water supply device that heats domestic water, etc.

[0322] In addition, in the above-mentioned embodiment, the battery 70 is used as an example of an endothermic source for generating heat for defrosting, but the endothermic source is not limited to the battery 70. For example, the temperature of an inverter, a PCU, a variable differential, a control device for ADAS, etc. may be adjusted. Furthermore, the temperature of a plurality of vehicle-mounted devices may be adjusted.

[0323] The inverter supplies power to the motor generator, etc. The PCU is a power control unit that performs power conversion and power distribution. The transaxle is a power transmission mechanism that integrates the transmission, differential gear, etc. The control device for ADAS is a control device for advanced driver assistance systems.

[0324] Furthermore, in the heat pump cycle device according to the present invention, when only the (e-3) hot gas defrost mode is executed as the defrost mode without switching the operation mode, the heat absorption source may not be provided.

[0325] The structure of the heat pump cycle device according to the present invention is not limited to the structure disclosed in the above-mentioned embodiment.

[0326] In the above-mentioned embodiment, an example in which the indoor condenser 13 is used as the heating unit is described, but the heating unit is not limited to the indoor condenser 13. For example, as the heating unit, a structure in which a high-temperature side pump, a water refrigerant heat exchanger, a heater core, etc. are arranged in a high-temperature side heat medium circulation circuit for circulating a high-temperature side heat medium may be used.

[0327] The high temperature side pump is a pump that presses the high temperature side heat medium to the water passage of the water refrigerant heat exchanger. The basic structure of the high temperature side pump is the same as that of the low temperature side pump 41. As the high temperature side heat medium, the same fluid as the low temperature side heat medium can be used. The water refrigerant heat exchanger is a heat exchanger that exchanges heat between the high pressure refrigerant discharged from the compressor 11 and the high temperature side heat medium pressurized from the high temperature side pump. The heater core is a heating heat exchanger that exchanges heat between the high temperature side heat medium heated in the water refrigerant heat exchanger and the supply air.

[0328] The heater core is arranged in the air passage of the indoor air conditioning unit 50 similarly to the indoor condenser 13. Thus, in the outdoor air absorption heating mode, the exhaust refrigerant can be used as a heat source to indirectly heat the supply air as the heating object via the high temperature side heat medium.

[0329] In the high-temperature-side heat medium circulation circuit, the amount of heat exchange between the refrigerant and the high-temperature-side heat medium in the water-refrigerant heat exchanger can be changed by changing the rotation speed of the high-temperature-side pump.

[0330] Therefore, the high temperature side pump is an operation mode switching unit that switches the operation mode by changing the heat exchange amount between the refrigerant and the high temperature side heat medium in the water refrigerant heat exchanger. More specifically, it is an operation mode switching unit that switches the operation mode by switching whether to perform heat exchange between the refrigerant and the high temperature side heat medium in the water refrigerant heat exchanger.

[0331] In addition, in the above-mentioned embodiment, the example of using the accumulator 23 as the gas-liquid separator for accumulating the excess liquid-phase refrigerant in the heat pump cycle 10 is described, but a receiver may be used instead of the accumulator 23. The receiver is a gas-liquid separator on the high-pressure side that separates the refrigerant flowing out of the indoor condenser 13 into gas and liquid and accumulates the excess liquid-phase refrigerant in the cycle.

[0332] Furthermore, when a receiver is used instead of the accumulator 23, in (c) the outdoor air heat absorption heating mode, the control device 60 controls the throttling opening of the cooling expansion valve 14c so that the superheat SHC becomes a preset reference superheat KSH.

[0333] In the above-mentioned embodiment, an example in which the second check valve 16b is used is described, but an evaporation pressure regulating valve may be used instead of the second check valve 16b. The evaporation pressure regulating valve is a variable throttling mechanism that maintains the refrigerant evaporation temperature in the indoor evaporator 18 at a predetermined temperature or higher. As the predetermined temperature, a temperature that can suppress the indoor evaporator 18 may be used.

[0334] As the evaporation pressure regulating valve, a variable throttling mechanism composed of a mechanical mechanism that increases the valve opening as the pressure of the refrigerant at the refrigerant outlet side of the indoor evaporator 18 increases can be used. In addition, as the evaporation pressure regulating valve, a variable throttling mechanism composed of an electrical mechanism similar to the heating expansion valve 14a or the like can also be used.

[0335] Furthermore, in the above-described embodiment, an example has been described in which the sixth three-way joint 12f as the bypass-side junction is arranged on the upstream side of the refrigerant flow of the chiller 20, but the present invention is not limited to this.

[0336] For example, it may be arranged on the downstream side of the refrigerant flow of the refrigerator 20. In this case, the refrigerant flowing out of the bypass side flow regulating valve 14d and the refrigerant flowing out of the refrigerant passage of the refrigerator 20 are homogeneously mixed when flowing through the refrigerant piping from the accumulator 23 and the sixth three-way joint 12f to the suction side of the compressor 11.

[0337] For example, the sixth three-way joint 12f may be eliminated and the end of the bypass passage 21a may be directly connected to the accumulator 23. Furthermore, a mixing portion may be provided to homogeneously mix the refrigerant decompressed in the cooling expansion valve 14c and the refrigerant flowing out of the bypass flow control valve 14d.

[0338] In addition, in the above-mentioned embodiment, in the (e-1-1) separate heat absorption defrost mode, an example is described in which the indoor air supply fan 52 is stopped in order not to heat the supply air in the outdoor condenser 13 serving as the heating unit, and the air passage on the indoor condenser 13 side is closed by the air mix door 54, but the example is not limited to this.

[0339] For example, a heating portion detour passage may be added to allow the refrigerant flowing out of the first three-way joint 12 to bypass the heating portion and be directed to the inlet side of the second three-way joint 12. Furthermore, in the (e-1-1) heat absorption defrosting mode alone, the refrigerant flowing out of the first three-way joint 12 may be directed to the heating portion detour passage. This also applies to the (e-2-1) heat absorption hot gas defrosting mode alone and the (e-3-1) hot gas defrosting mode alone.

[0340] In addition, in the above-mentioned embodiment, an example of using R1234yf as the refrigerant of the heat pump cycle 10 is described, but the invention is not limited thereto. For example, R134a, R600a, R410A, R404A, R32, R407C, etc. may also be used. Alternatively, a mixed refrigerant obtained by mixing a plurality of these refrigerants may also be used. Furthermore, carbon dioxide may also be used as the refrigerant to form a supercritical refrigeration cycle in which the refrigerant pressure on the high-pressure side is higher than the critical pressure of the refrigerant.

[0341] In the above-mentioned embodiment, an example in which PAG oil (ie, polyalkylene glycol oil) is used as the refrigeration oil is described, but the present invention is not limited thereto. For example, POE (ie, polyol ester) or the like may be used.

[0342] In addition, in the above-mentioned embodiment, an example of using ethylene glycol aqueous solution as a heat medium and a low-temperature side heat medium is described, but it is not limited to this. For example, a solution containing dimethylpolysiloxane or a nanofluid, an antifreeze solution, a water-based liquid refrigerant containing alcohol, a liquid medium containing oil, etc., etc. may also be used.

[0343] The control sensor group connected to the input side of the control device 60 is not limited to the detection unit disclosed in the above-mentioned embodiment, and various detection units can be added as needed.

[0344] The control method of the heat pump cycle device according to the present invention is not limited to the control method disclosed in the above-mentioned embodiment.

[0345] In the above-mentioned embodiment, the vehicle air conditioning device 1 capable of executing various operation modes has been described. However, the heat pump cycle device according to the present invention does not necessarily need to be capable of executing all of the above-mentioned operation modes.

[0346] As long as at least the (e-3) hot gas defrost mode can be executed, the effect of quickly completing the defrosting of the outdoor air heat exchanger 15 without the need for an endothermic source can be achieved. In addition, as long as at least the (e-2) endothermic hot gas defrost mode can be executed, the effect of efficiently and quickly completing the defrosting of the outdoor air heat exchanger 15 can be achieved.

[0347] Furthermore, the vehicle air conditioner 1 may be capable of executing other operation modes. For example, when the evaporation pressure regulating valve described above is provided, the parallel dehumidification and heating mode may be capable of being executed.

[0348] In the heat pump cycle 10 in the parallel dehumidification heating mode, the refrigerant discharged from the compressor 11 circulates in the order of the indoor condenser 13, the heating expansion valve 14a in the throttling state, the outdoor air heat exchanger 15, the low-pressure side passage 21c, the accumulator 23, and the suction port of the compressor 11. At the same time, it is sufficient to switch to a refrigerant circuit in which the refrigerant discharged from the compressor 11 circulates in the order of the indoor condenser 13, the high-pressure side passage 21b, the cooling expansion valve 14b in the throttling state, the indoor evaporator 18, the accumulator 23, and the suction port of the compressor 11. That is, it is sufficient to switch to a refrigerant circuit in which the indoor evaporator 18 and the outdoor air heat exchanger 15 are connected in parallel with respect to the flow of the refrigerant.

[0349] In the parallel dehumidification and heating mode, the control device 60 may appropriately control the operations of other control target devices, similarly to the (b) dehumidification and heating mode.

[0350] In the parallel dehumidification and heating mode, the supply air cooled and dehumidified in the indoor evaporator 18 is heated again in the indoor condenser 13 and supplied to the vehicle interior. Thus, dehumidification and heating in the vehicle interior are achieved. In the parallel dehumidification and heating mode, the refrigerant depressurized in the heating expansion valve 14a flows into the outdoor air heat exchanger 15, and the refrigerant absorbs heat from the outdoor air in the outdoor air heat exchanger 15. Therefore, the parallel dehumidification and heating mode includes a heating mode for heating a heating object.

[0351] In the above-mentioned (d) hot gas heating mode, etc., an example is described in which the throttling opening of the cooling expansion valve 14c is controlled so that the refrigerant on the outlet side of the refrigerator 20 approaches the saturated gas phase refrigerant, but the present invention is not limited to this.

[0352] For example, the throttling opening of the cooling expansion valve 14c or the like may be controlled so that the refrigerant on the outlet side of the cold machine 20 approaches a gas-liquid two-phase refrigerant containing a liquid-phase refrigerant appropriately mixed with refrigeration oil. That is, the throttling opening of the cooling expansion valve 14c or the like may be controlled so that the dryness Rxc of the refrigerant on the outlet side of the cold machine 20 becomes a relatively high value.

[0353] In addition, in the (e-2) heat absorption hot gas defrost mode, (e-3) hot gas defrost mode, etc. of the above-mentioned embodiments, an example of controlling the throttling opening of the heating expansion valve 14a so that the outdoor air side refrigerant pressure P2 is close to the reference defrost pressure KPdf is described, but it is not limited to this.

[0354] For example, the throttling opening of the cooling expansion valve 14c may be controlled so that the outside air side refrigerant pressure P2 approaches the reference defrost pressure KPdf, and the throttling opening of the heating expansion valve 14a may be controlled so that the refrigerant on the outlet side of the cold machine 20 approaches the saturated gas-phase refrigerant. For example, the opening ratio of the throttling opening of the heating expansion valve 14a to the throttling opening of the cooling expansion valve 14c may be controlled so that the outside air side refrigerant pressure P2 approaches the reference defrost pressure KPdf, and the refrigerant on the outlet side of the cold machine 20 approaches the saturated gas-phase refrigerant.

[0355] That is, the control device 60 may control the operation of at least one of the heating expansion valve 14a and the cooling expansion valve 14c so that the temperature of the refrigerant flowing into the outdoor air heat exchanger 15 approaches the reference defrosting temperature KTdf.

[0356] In addition, in the above-mentioned embodiment, an example is described in which the outside air heat exchanger 15 is defrosted and the vehicle interior is heated when the heating switch of the operation panel 69 is turned on in the defrost mode, but the present invention is not limited thereto. For example, the outside air heat exchanger 15 may be defrosted and the vehicle interior may be heated when the outside air temperature Tam becomes lower than a preset reference heating temperature.

[0357] In addition, in the above Figure 4The frosting condition and the end condition that can be used in the control process are not limited to the conditions disclosed in the above-mentioned embodiment. For example, the frosting condition may also be a condition that is satisfied when the time when the outside air temperature Tam becomes below the preset frost determination outside air temperature KTamf becomes longer than a preset reference time. For example, the end condition may also be a condition that is satisfied when the defrosting elapsed time from the start of the operation of the defrosting mode becomes longer than a preset reference defrosting time.

[0358] The features of the heat pump cycle device disclosed in this specification are as follows.

[0359] (Item 1)

[0360] The heat pump circulation device has:

[0361] A compressor (11) which compresses and discharges a refrigerant;

[0362] an upstream branching portion (12a) for branching the flow of the refrigerant discharged from the compressor;

[0363] a heating section (13) which uses the refrigerant flowing out of one outlet of the upstream branch section as a heat source to heat a heating object;

[0364] an outside air heat exchange section (15) for exchanging heat between the refrigerant and outside air;

[0365] an upstream pressure reducing section (14a) for reducing the pressure of the refrigerant flowing into the outdoor air heat exchange section;

[0366] a downstream-side decompression section (14c) for decompressing the refrigerant flowing out of the outdoor air heat exchange section;

[0367] A bypass passage (21a) that guides the refrigerant flowing out of the other outflow port of the upstream branch portion to the suction port side of the compressor; and

[0368] a bypass side flow rate adjustment unit (14d) for adjusting the flow rate of the refrigerant flowing through the bypass passage;

[0369] In a heating mode in which the heating unit heats the heating object, the refrigerant decompressed in the upstream-side decompression unit flows into the outdoor air heat exchange unit, and the refrigerant absorbs heat of the outdoor air in the outdoor air heat exchange unit.

[0370] In the defrost mode for removing frost attached to the outside air heat exchange portion, the refrigerant flowing out from the outlet on one side of the upstream side branch portion is caused to flow into the outside air heat exchange portion to dissipate heat, and the refrigerant flowing out of the outside air heat exchange portion is decompressed in the downstream side pressure reducing portion, and the refrigerant decompressed in the downstream side pressure reducing portion is mixed with the refrigerant flowing out of the bypass side flow adjusting portion and is sucked into the compressor.

[0371] (Item 2)

[0372] In the heat pump cycle device described in Item 1, in the defrost mode, the refrigerant flowing out from one outlet of the upstream branch portion is decompressed in the upstream pressure reducing portion, and the refrigerant flowing out of the upstream pressure reducing portion flows into the outdoor air heat exchange portion to dissipate heat.

[0373] (Item 3)

[0374] In the heat pump circulation device described in Item 1 or 2, in the defrost mode, the refrigerant flowing out from the outlet on one side of the upstream branch portion is caused to flow into the heating portion to heat the heating object, the refrigerant flowing out from the heating portion is depressurized in the upstream side pressure reducing portion, and the refrigerant flowing out from the upstream side pressure reducing portion is caused to flow into the outdoor air heat exchange portion to dissipate heat.

[0375] (Item 4)

[0376] In the heat pump circulation device described in Item 2 or 3, in the defrost mode, the operation of at least one of the upstream pressure reducing section and the downstream pressure reducing section is controlled so that the temperature of the refrigerant flowing into the outdoor air heat exchange section approaches a predetermined reference defrost temperature (KTdf).

[0377] (Item 5)

[0378] The heat pump cycle device according to any one of items 1 to 4 comprises a defrosting heat absorbing section (20) which causes the refrigerant to absorb defrosting heat for defrosting the outdoor air heat exchange section.

[0379] In the defrost mode, when the refrigerant can absorb the defrost heat in the defrost heat absorbing portion, the refrigerant absorbs the defrost heat in the defrost heat absorbing portion.

[0380] The present invention is described based on the embodiments, but it should be understood that the present invention is not limited to the embodiments and structures. The present invention also includes various modifications and variations within the scope of equality. In addition, various combinations and methods, which further include only one element, other combinations and methods above or below thereof, are also included in the scope and thought range of the present invention.

Claims

1. A heat pump circulation device, characterized in that: have: A compressor (11) which compresses and discharges a refrigerant; an upstream branching portion (12a) for branching the flow of the refrigerant discharged from the compressor; a heating section (13) which uses the refrigerant flowing out of one outlet of the upstream branch section as a heat source to heat a heating object; an outside air heat exchange section (15) for exchanging heat between the refrigerant and outside air; an upstream pressure reducing section (14a) for reducing the pressure of the refrigerant flowing into the outdoor air heat exchange section; a downstream-side decompression section (14c) for decompressing the refrigerant flowing out of the outdoor air heat exchange section; A bypass passage (21a) that guides the refrigerant flowing out of the other outflow port of the upstream branch portion to the suction port side of the compressor; and a bypass side flow rate adjustment unit (14d) for adjusting the flow rate of the refrigerant flowing through the bypass passage; In a heating mode in which the heating unit heats the heating object, the refrigerant decompressed in the upstream-side decompression unit flows into the outdoor air heat exchange unit, and the refrigerant absorbs heat of the outdoor air in the outdoor air heat exchange unit. In the defrost mode for removing frost attached to the outside air heat exchange portion, the refrigerant flowing out from the outlet on one side of the upstream side branch portion is caused to flow into the outside air heat exchange portion to dissipate heat, and the refrigerant flowing out of the outside air heat exchange portion is decompressed in the downstream side pressure reducing portion, and the refrigerant decompressed in the downstream side pressure reducing portion is mixed with the refrigerant flowing out of the bypass side flow adjusting portion and is sucked into the compressor.

2. The heat pump circulation device according to claim 1, characterized in that: In the defrost mode, the upstream pressure reducing portion decompresses the refrigerant flowing out from one outlet of the upstream branch portion, and causes the refrigerant flowing out from the upstream pressure reducing portion to flow into the outdoor air heat exchange portion to dissipate heat.

3. The heat pump circulation device according to claim 1, characterized in that: In the defrost mode, the refrigerant flowing out from the outlet on one side of the upstream branch portion is caused to flow into the heating portion to heat the heating object, the refrigerant flowing out from the heating portion is depressurized in the upstream pressure reducing portion, and the refrigerant flowing out from the upstream pressure reducing portion is caused to flow into the outdoor air heat exchange portion to dissipate heat.

4. The heat pump circulation device according to claim 2 or 3, characterized in that: In the defrost mode, the operation of at least one of the upstream pressure reducing unit and the downstream pressure reducing unit is controlled so that the temperature of the refrigerant flowing into the outdoor air heat exchange unit approaches a preset reference defrost temperature (KTdf).

5. The heat pump circulation device according to any one of claims 1 to 3, characterized in that: A defrosting heat absorbing section (20) is provided, wherein the defrosting heat absorbing section causes the refrigerant to absorb defrosting heat for defrosting the outdoor air heat exchange section. In the defrost mode, when the refrigerant can absorb the defrost heat in the defrost heat absorbing portion, the refrigerant absorbs the defrost heat in the defrost heat absorbing portion.

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