Vehicle air conditioning device

Abstract

The present invention suppresses the retention of a refrigerant in an external heat exchange unit during a hot-gas heating operation, and ensures the heating capability during the hot-gas heating operation. A vehicle air-conditioning device is provided with a control device that controls a refrigerant circuit, a heat medium circuit, and an air-conditioning unit, the refrigerant circuit having a hot gas bypass that decompresses at least a portion of a refrigerant compressed by a compressor and returns the refrigerant to the compressor without passing through an indoor heat exchange unit and an external heat exchange unit. The control device can execute a hot air heating operation for heating the interior of the vehicle by radiating a part of the refrigerant compressed by the compressor through the indoor heat exchange unit without causing the refrigerant to absorb heat in the external heat exchange unit, and a heat absorption heating operation for causing the refrigerant to absorb heat through the external heat exchange unit. And a control unit for determining whether or not it is necessary to recover the refrigerant from the external heat exchange unit, and if it is determined that it is necessary to recover the refrigerant, performing a refrigerant recovery process for recovering the refrigerant from the external heat exchange unit after the execution of the previous air-conditioning operation or before the execution of the hot-air heating operation.

Description

Technical Field

[0001] The present invention relates to a vehicle air conditioning device. Background Art

[0002] Air conditioning apparatuses for electric vehicles (EVs) that do not have a heat source of a combustion system such as an engine or for vehicles with a low heat source of a combustion system have been known that use a heat pump (refrigerant circuit) as a heat source.

[0003] In the case of an air conditioner using a heat pump, the external heat exchanger functions as a heat absorber during heating operation, and obtains a heating heat source from the outside air. Therefore, if the outside air temperature becomes extremely low, it becomes difficult to absorb heat from the outside air, and the heating capacity is greatly reduced. In this regard, if an electric heater such as a PTC heater is used to ensure a heat source, the battery consumption increases, and in the case of electric vehicles, there is a concern that this may have a negative impact on the cruising range, and the equipment of a PTC heater may increase the manufacturing cost of the air conditioner.

[0004] Heating using hot gas from high-temperature and high-pressure refrigerant discharged from a compressor of a refrigerant circuit is a heating method that does not absorb heat and is expected to be effective heating in extremely low temperature environments. In this hot gas heating, the interior heat exchanger of a vehicle air conditioner functions as a radiator (interior condenser), into which the high-temperature and high-pressure refrigerant discharged from the compressor flows directly, and after the refrigerant discharged from the radiator is depressurized, it returns to the compressor via an accumulator instead of an external heat exchanger (see Patent Document 1 below).

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-196017

[0006] In order to make hot air heating operate continuously and efficiently, it is necessary to limit the heat dissipation in the refrigerant circuit to the indoor condenser as much as possible, so that the heat dissipation in the refrigerant circuit and the energy consumption (input heat) of the compressor are balanced. In addition, the liquid refrigerant condensed by the heat dissipation in the indoor condenser must not evaporate but be gasified and returned to the compressor.

[0007] In order to achieve the above situation, on the basis of the refrigerant flow path in which the high-pressure and high-temperature refrigerant discharged from the compressor is decompressed after dissipating heat in the indoor condenser and returns to the compressor, a bypass refrigerant flow path (hot gas bypass) for hot gas heating is provided, which diverts a part of the high-temperature and high-pressure refrigerant discharged from the compressor and decompresses it and returns it to the compressor without passing through the heat exchanger.

[0008] If such a hot gas bypass is provided, the gas refrigerant passing through the hot gas bypass can be mixed with the liquid refrigerant condensed by heat dissipation in the indoor heat exchanger, and the refrigerant rich in gas can be returned to the compressor. In addition, by increasing the refrigerant flow rate flowing through the hot gas bypass, the heat dissipation in the indoor heat exchanger can be suppressed, so by adjusting the refrigerant flow rate flowing through the hot gas bypass, the balance between the heat dissipation of the refrigerant circuit and the input heat input to the compressor can be maintained.

[0009] In a refrigerant circuit that can switch between such hot gas heating operation and normal heating operation that absorbs heat from an external heat exchanger, if there is refrigerant in the external heat exchanger during the hot gas heating operation, the refrigerant pressure of the refrigerant flow path in the hot gas heating operation becomes higher than that of the refrigerant flow path on the outlet side of the external heat exchanger, regardless of whether it is the refrigerant flow path on the high-pressure side or the refrigerant flow path on the low-pressure side after pressure reduction, so there is no refrigerant flow path for the refrigerant in the external heat exchanger to flow out.

[0010] Therefore, when the hot gas heating operation is started, the refrigerant in the external heat exchanger is retained therein, and the amount of refrigerant used in the hot gas heating operation is reduced. If this phenomenon occurs, the refrigerant flow rate sucked into the compressor during the hot gas heating operation cannot be increased, and the refrigerant pressure cannot be increased to a required value, resulting in a problem that sufficient heating capacity cannot be obtained. Summary of the invention

[0011] The present invention aims to address such a problem. That is, the present invention aims to suppress the refrigerant from stagnating in the external heat exchanger during hot gas heating operation and to ensure the heating capacity during hot gas heating operation.

[0012] In order to solve the above-mentioned problems, the present invention has the following configurations. The vehicle air conditioning device comprises: a refrigerant circuit including a compressor, an indoor heat exchange part, an external heat exchange part and a refrigerant heat medium heat exchanger; a heat medium circuit that circulates a heat medium that exchanges heat with a refrigerant through the refrigerant heat medium heat exchanger; an air conditioning unit that has the indoor heat exchange part disposed therein; and a control device that controls the refrigerant circuit, the heat medium circuit and the air conditioning unit, wherein the refrigerant circuit has a hot gas bypass that decompresses at least a portion of the refrigerant compressed by the compressor and returns to the compressor without passing through the indoor heat exchange part and the external heat exchange part, and the control device The device is configured to execute hot air heating operation and heat absorption heating operation. In the hot air heating operation, the refrigerant is not allowed to absorb heat in the external heat exchange part, but a part of the refrigerant compressed by the compressor is dissipated through the indoor heat exchange part to heat the vehicle interior. In the heat absorption heating operation, the refrigerant is allowed to absorb heat through the external heat exchange part, and the control device determines whether it is necessary to recover the refrigerant from the external heat exchange part. When the control device determines that the refrigerant needs to be recovered, the control device performs a refrigerant recovery process to recover the refrigerant from the external heat exchange part after the previous air-conditioning operation is executed or before the hot air heating operation is executed.

[0013] The present invention having such features can suppress the refrigerant from stagnating in the external heat exchanger during the hot gas heating operation, thereby ensuring the heating capacity during the hot gas heating operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is an explanatory diagram showing an example of the system configuration of a vehicle air conditioning device according to an embodiment of the present invention. Figure 2 It is an explanatory diagram showing a control device for a vehicle air conditioning system according to an embodiment of the present invention. Figure 3 It is an explanatory diagram showing the operation of the refrigerant circuit in the hot gas heating operation of the vehicle air conditioner according to the embodiment of the present invention. Figure 4 It is an explanatory diagram showing the operation of the refrigerant circuit in the heat absorption heating operation of the vehicle air conditioning system according to the embodiment of the present invention. Figure 5 It is an explanatory diagram showing the refrigerant recovery process. Figure 6 It is an explanatory diagram showing a basic operation flow of the vehicle air conditioning device according to the embodiment of the present invention. Figure 7 This is an explanatory diagram showing a configuration example of a control device in an electric vehicle (EV) including a vehicle air conditioner. DETAILED DESCRIPTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals in different figures represent parts with the same function, and repeated descriptions in the figures are appropriately omitted. In addition, the bold lines in the refrigerant circuit 10 in the figure represent refrigerant flow paths for refrigerant circulation, the black bold lines in the bold lines represent high-pressure refrigerant flow, and the gray bold lines represent low-pressure refrigerant flow after decompression. In addition, the dotted lines in the refrigerant circuit 10 represent refrigerant flow paths through which refrigerant does not circulate.

[0016] (System Structure) Figure 1 A configuration example of a vehicle air conditioning device 1 according to an embodiment of the present invention is shown. The configuration example shown here is just an example, and the specific configuration is not particularly limited.

[0017] The vehicle air conditioning device 1 includes a refrigerant circuit 10 and an air conditioning unit 20. The refrigerant circuit 10 includes a compressor 2, indoor heat exchangers 21 and 22 provided inside the air conditioning unit 20, and an external heat exchanger 11 provided outside the vehicle, which are arranged along a refrigerant flow path. The indoor heat exchangers 21 and 22 are provided to exchange heat between the air flowing through the air conditioning unit 20 and the refrigerant, and the external heat exchanger 11 is provided to exchange heat between the external air and the refrigerant outside the vehicle.

[0018] The compressor 2 of the refrigerant circuit 10 compresses the refrigerant and circulates the refrigerant. The refrigerant compressed by the compressor 2 is decompressed to a necessary pressure in an appropriately selected refrigerant flow path through, for example, a first decompression section V1, a second decompression section V2, a third decompression section V3, and a fourth decompression section V4, which are expansion valves. The refrigerant circuit 10 is provided with flow path switching valves 12 and 13 for switching the refrigerant flow path, and check valves 14 and 15 for limiting the flow direction of the refrigerant are provided as needed. Moreover, on the upstream side of the compressor 2 in the refrigerant circuit 10, a liquid accumulator 16 for recovering liquid refrigerant and separating the refrigerant into gas and liquid is provided.

[0019] As described above, the air conditioning unit 20 is provided with indoor heat exchangers 21 and 22 inside, and the air introduced from indoor or outdoor by the blower 23 selectively passes through the indoor heat exchangers 21 and 22 and is blown indoors. The air conditioning unit 20 is provided with a damper 24. When the damper 24 is fully opened as shown in the figure, the air introduced by the blower 23 passes through both indoor heat exchangers 21 and 22 and is blown indoors, and when the damper 24 is fully closed, the air introduced by the blower 23 passes only through the indoor heat exchanger 22 and is blown indoors. Another damper 25 provided in the air conditioning unit 20 switches the air introduced to the blower 23 between indoor and outdoor, and selectively closes the air inlet 25A connected to the outdoor and the air inlet 25B connected to the indoor.

[0020] In addition, in the above-mentioned external heat exchanger 11 and indoor heat exchangers 21 and 22, an example in which the refrigerant and the air directly exchange heat is described, but the refrigerant and the air may also exchange heat indirectly via a heat medium that exchanges heat with the refrigerant. That is, it is also possible to configure the refrigerant to absorb heat from the air via the heat medium, or to release heat from the refrigerant to the air via the heat medium.

[0021] In addition, the vehicle air conditioning device 1 is provided with a heat medium circuit 30 as required. The heat medium circuit 30 circulates the heat medium through a circulation pump 31, heats the heat medium through a heater (ECH: Electric Coolant Heater) 32, or recovers waste heat from a temperature control object such as a battery through a temperature control object heat exchanger 33. In addition, a refrigerant heat medium heat exchanger 34 is provided in the refrigerant circuit 10 and the heat medium circuit 30, and the refrigerant heat medium heat exchanger 34 performs heat exchange between the refrigerant and the heat medium through a flow channel 34A through which the refrigerant flows and a flow channel 34B through which the heat medium flows.

[0022] (Control device) The vehicle air conditioning device 1 includes: Figure 2 The control device 100 shown in FIG. The control device 100 controls the aforementioned refrigerant circuit 10 and the air conditioning unit 20 based on various input signals (air conditioning instruction signal, charger connection signal, etc.) and detection signals from the sensor unit 40, and controls the heat medium circuit 30 as needed.

[0023] The sensor unit 40 that inputs a detection signal to the control device 100 includes, for example, an outside air sensor 41 that detects outside air conditions such as outside air temperature and outside air humidity, a compressor current sensor 42 for detecting power consumption (energy consumption) of the compressor 2, a refrigerant temperature sensor 43 and a refrigerant pressure sensor 44 that detect the state of the refrigerant, a passenger sensor 45 that detects the presence or absence of passengers in the vehicle cabin, and an air supply temperature sensor 46 that detects the air supply temperature of the air conditioning unit 20. These sensors are only examples. The sensor unit 40 includes various sensors for detecting information required when the control device 100 performs various controls.

[0024] In the refrigerant circuit 10, the control objects of the control device 100 are the compressor 2, the first decompression part V1, the second decompression part V2, the third decompression part V3, and the fourth decompression part V4, etc. In the air conditioning unit 20, the control objects of the control device 100 are the blower 23 and the dampers 24 and 25, etc. In the heat medium circuit 30, the control objects of the control device 100 are the circulation pump 31, etc. In addition, the control device 100 controls the vehicle air conditioning device 1 or the notification device (for example, a display device such as an indicator and a monitor, a sound device such as an audio device) 3 provided in the vehicle according to the processing result of the control device 100.

[0025] (Hot gas heating operation) In the hot air heating operation, the refrigerant does not absorb heat in the external heat exchanger 11, but part or all of the refrigerant compressed by the compressor 2 dissipates heat through the indoor heat exchanger 21 to heat the vehicle interior.

[0026] use Figure 3 The operation of the refrigerant circuit 10 in the hot air heating operation (including the preparatory operation) is described. In this operation, a part of the high-temperature and high-pressure refrigerant discharged from the compressor 2 passes through the indoor heat exchanger 21 and the flow path switching valve 12, is reduced in pressure by the third pressure reducing unit V3 to become a low-pressure refrigerant, passes through the refrigerant heat medium heat exchanger 34, and is separated into gas and liquid by the accumulator 16, and returns to the compressor 2. At this time, in the refrigerant circuit 10, the first pressure reducing unit V1 is fully closed, so that the refrigerant does not flow to the external heat exchanger 11. In addition, the fourth pressure reducing unit V4 is fully closed, and the refrigerant does not flow to the indoor heat exchanger 22.

[0027] The refrigerant circuit 10 has a hot gas bypass 10V that reduces the pressure of at least a portion of the refrigerant compressed by the compressor 2 and returns to the compressor 2 without passing through the indoor heat exchanger 21 and the external heat exchanger 11. In the hot gas bypass 10V, a portion of the high-temperature and high-pressure refrigerant is branched at a branch point P1 immediately downstream of the compressor 2, is reduced in pressure by the second pressure reducing section V2 (hot gas valve), and merges with the low-pressure refrigerant reduced in pressure by the third pressure reducing section V3 at a confluence point P2 immediately upstream of the accumulator 16.

[0028] By providing such a hot gas bypass 10V, the gas refrigerant passing through the hot gas bypass 10V can be mixed with the liquid refrigerant condensed by heat dissipation in the indoor heat exchanger 21, and the refrigerant becomes gas-rich and then returns to the compressor 2. In addition, by increasing the refrigerant flow rate flowing through the hot gas bypass 10V, the heat dissipation in the indoor heat exchanger 21 can be suppressed, and by adjusting the refrigerant flow rate flowing through the hot gas bypass 10V by opening and closing the second pressure reducing unit V2 (hot gas valve), the balance between the heat dissipation of the refrigerant circuit 10 and the input heat input to the compressor 2 can be maintained.

[0029] The refrigerant flow during the hot air heating operation is decompressed by the third decompression section V3 in the flow passage passing through the indoor heat exchanger 21, so it becomes a high-pressure refrigerant on the upstream side of the third decompression section V3 and becomes a low-pressure refrigerant on the downstream side of the third decompression section V3. At this time, heat exchange is not performed in the refrigerant heat medium heat exchanger 34 in the low-pressure side flow passage, which is important for maintaining the heating capacity. In addition, in the air conditioning unit 20, the air introduced by the blower 23 is heated by heat dissipation in the indoor heat exchanger 21 and blown into the vehicle interior.

[0030] (Ready to operate) In the preparatory operation performed when the hot air heating operation is started, until the refrigerant reaches a predetermined state, heat dissipation in the indoor heat exchanger 21 is not performed or suppressed, and the refrigerant is circulated through the refrigerant circuit 10. One method is to perform the operation of the refrigerant circuit 10 in the hot air heating operation described above while stopping or suppressing the blower 23 of the air conditioning unit 20. In addition, another method is to fully close the damper 24 in the state where the blower 23 of the air conditioning unit 20 is operated, so that the indoor heat exchanger 21 is not ventilated, and the operation of the refrigerant circuit 10 in the hot air heating operation described above is performed.

[0031] In the former method, since the wind from the air conditioning unit 20 is stopped or suppressed, it is necessary to notify the passengers that the preparatory operation is being executed as described later. In contrast, in the latter method, the wind that does not pass through the indoor heat exchanger 21 is temporarily circulated from the air conditioning unit 20, so that the wind volume can be adjusted by the passengers, thereby eliminating the discomfort of the passengers.

[0032] (Heat absorption heating operation) use Figure 4 The operation of the refrigerant circuit 10 during the endothermic heating operation will be described. In the refrigerant circuit 10 during the endothermic heating operation, the second decompression section V2, the third decompression section V3, the fourth decompression section V4 and the flow path switching valve 12 are all fully closed.

[0033] In the heat absorption heating operation, the high-temperature and high-pressure refrigerant discharged from the compressor 2 passes through the indoor heat exchanger 21 in the air conditioning unit 20, is decompressed by the first pressure reducing part V1, and the low-pressure refrigerant passes through the external heat exchanger 11, and returns to the compressor 2 via the flow path switching valve 13, the check valve 14 and the accumulator 16. At this time, the high-pressure refrigerant discharged from the compressor 2 is condensed and radiates heat by the indoor heat exchanger 21, is decompressed by the first pressure reducing part V1 to become a low-pressure refrigerant, and absorbs heat and evaporates by the external heat exchanger 11, and returns to the compressor 2. In addition, in the air conditioning unit 20, the air introduced by the blower 23 is heated by the heat dissipation in the indoor heat exchanger 21 and is blown into the vehicle interior.

[0034] (Refrigerant recovery and treatment) If executed Figure 3 In the hot gas heating operation shown in FIG. 1 , both the upstream and downstream sides of the external heat exchanger 11 of the refrigerant circuit 10 are connected to the high-pressure refrigerant flow path. Therefore, if there is condensed refrigerant in the external heat exchanger 11 before the hot gas heating operation, the condensed refrigerant is retained and the refrigerant flow rate during the hot gas heating operation is reduced, which becomes a cause of the decrease in heating capacity during the hot gas heating operation. In order to avoid the above situation, it is effective to perform refrigerant recovery processing after the heat absorption heating operation is performed or before the hot gas heating operation is performed.

[0035] As a treatment method for refrigerant recovery, such as Figure 5 As shown, in the state where the second pressure reducing part V2 is closed (the hot gas bypass 10V is closed), the high-pressure refrigerant from the compressor 2 flows directly to the third pressure reducing part V3 through the indoor heat exchanger 21. In addition, the flow path switching valve 13 is opened, and the downstream side of the external heat exchanger 11 is connected to the upstream side (junction point P2) of the accumulator 16 via the check valve 14. As a result, the downstream side of the external heat exchanger 11 is connected to the low-pressure refrigerant flow path on the downstream side of the third pressure reducing part V3. As a result, the refrigerant retained in the external heat exchanger 11 is recovered by being attracted by the pressure of the low-pressure refrigerant flow path.

[0036] exist Figure 5 In the circuit state of the refrigerant recovery processing shown, the upstream side of the third pressure reducing section V3 is a high-pressure refrigerant flow path in which only the indoor heat exchanger 21 dissipates heat, and the downstream side of the third pressure reducing section V3 becomes a low-pressure refrigerant flow path that can absorb heat from the heat medium circuit 30 through the refrigerant heat medium heat exchanger 34.

[0037] In addition, since the refrigerant can be recovered even without absorbing heat from the heat medium circuit 30, Figure 5 As shown, the refrigerant accumulated in the external heat exchanger 11 can be recovered to the accumulator 16 by continuing the circulation of the illustrated refrigerant for a certain period of time in a state where the circulation of the heat medium circuit 30 is stopped.

[0038] In addition, as another processing method, the heat dissipation from the external heat exchanger 11 is suppressed. Figure 4 To suppress heat dissipation from the external heat exchanger 11, a fan (not shown) that supplies external air to the external heat exchanger 11 may be stopped, or an air intake grill (not shown) in front of the external heat exchanger 11 may be closed.

[0039] By performing such a refrigerant recovery process after the previous outside air heat absorption heating operation or the previous other air conditioning operation or before the hot gas heating operation, a sufficient heating capacity can be ensured during the hot gas heating operation.

[0040] (Basic Action) use Figure 6 The basic operation of the vehicle air conditioning device 1 implemented by the control device 100 will be described. When the vehicle air conditioning device 1 starts to operate, it enters a signal waiting state for an air conditioning instruction signal (step S01). If a heating instruction is input (step S01: Yes), the process moves to the next step S02. If an instruction other than the heating instruction (for example, a cooling instruction) is input (step S01: No), the process moves to other air conditioning control corresponding to the instruction (step S01A).

[0041] In the next step S02, it is determined whether the hot air heating operation is to be performed. Since the hot air heating operation is mainly performed when the heat absorption heating cannot be performed, for example, when the outside air sensor 41 detects an extremely low temperature condition and it is determined that the hot air heating operation should be performed (step S02: Yes), the process moves to the next step S03. In the case where it is determined in step S02 that the hot air heating operation is not to be performed (step S02: No), the above-mentioned intake air heating operation (step S11) is performed.

[0042] In step S03, it is determined whether condensed refrigerant is accumulated in the external heat exchanger 11, the refrigerant heat medium heat exchanger 34, etc. in the refrigerant circuit 10 based on the state of the refrigerant in the refrigerant circuit 10, the state of the heating operation before startup, etc. If it is determined that refrigerant is accumulated and needs to be recovered (step S03: yes), refrigerant recovery processing (step S04) is performed. In addition, if it is determined in step S03 that refrigerant recovery is not required (step S03: no), the refrigerant recovery processing (step S04) is skipped. In addition, if the refrigerant recovery processing is performed in steps S09 and S10 after the heating is completed, steps S03 and S04 here can be omitted.

[0043] In step S05, the aforementioned preparatory operation performed when the hot air heating operation is started is performed. In the preparatory operation, the operation of the refrigerant circuit 10 in the hot air heating operation is performed in a state where heat dissipation from the refrigerant circuit 10 is not or is suppressed, so that the circulating refrigerant becomes a high-pressure state and energy is accumulated in the refrigerant. In this preparatory operation (step S05), as described above, the blower 23 of the air conditioning unit 20 is stopped.

[0044] Then, in step S06, the preparatory operation (step S05) is continued until it is determined that the refrigerant state is suitable for hot air heating operation (step S06: No). During this period, the passengers in the vehicle are notified that the preparatory operation for hot air heating operation is being performed, so that the passengers in the vehicle will not feel uneasy or uncomfortable due to equipment failure when air is not blown out from the air-conditioning unit 20 (step S06A).

[0045] In the notification to the passenger here (passenger notification: step S06A), an output is performed from the control device 100 to the notification device 3 to notify the passenger that the aforementioned preparatory operation is being executed. As an example, the display is performed on a display device such as an indicator or a monitor provided in the vehicle by flashing or by displaying on the monitor. As another example, a sound or a predetermined notification sound is emitted from a speaker provided in the vehicle to notify the passenger that the aforementioned preparatory operation is being executed. In this way, the passenger can recognize that the current situation of not blowing air is not due to a device failure, etc., but is a normal preparatory operation for the hot air heating operation.

[0046] If it is confirmed that sufficient energy has been stored in the refrigerant during the preparatory operation based on the detection results of the refrigerant pressure and the power consumption of the compressor 2, the preparatory operation is determined to be completed (step S06: Yes), and the hot air heating operation with air supply is performed (step S07).

[0047] The hot air heating operation is performed until the heating end instruction is input (step S08: No). If the heating end instruction is input (step S08: Yes), the necessity of refrigerant recovery is determined (step S09) and the refrigerant recovery process is performed if necessary (step S10) as in steps S03 and S04, and the air conditioning operation is terminated. In addition, when steps S03 and S04 are performed at the next air conditioning operation, steps S09 and S10 can be omitted.

[0048] When heat absorption heating operation is performed in step S11, the operation continues until the subsequent heating end instruction is issued (step S12: No). If the heating end instruction is issued (step S12), the necessity of refrigerant recovery is determined (step S09) and the refrigerant recovery process is performed if necessary (step S10), and the air conditioning operation is terminated.

[0049] (Structure of control device in electric vehicle (EV)) like Figure 7 As shown, the control device 100 provided in the vehicle air conditioning device 1 is configured as one ECU connected to various ECUs (Electronic Control Units) that control the electric vehicle (EV) via the vehicle network L. The control device 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, an input / output I / F (Interface) 104, and an in-vehicle communication I / F (Interface) 105, and the hardware components are connected to each other via a bus 106.

[0050] CPU101 controls the control device 100 by executing various programs stored in ROM102. ROM102 is a non-volatile memory. For example, ROM102 stores programs executed by CPU101, data required for CPU101 to execute programs, etc. RAM103 is a main storage device such as DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory). For example, RAM103 functions as a work area used by CPU101 when executing a program. The input and output I / F104 is connected to various sensors and monitors installed in the EV, inputs data to CPU101, and outputs data obtained by CPU101 calculation and processing. The in-vehicle communication I / F105 controls the data transmission and reception with other ECUs set in the EV by connecting to the vehicle network L.

[0051] The control device 100 receives data on surrounding environment information or data on the operating status of the EV via the input / output I / F 104 and the in-vehicle communication I / F 105 , and controls the vehicle air conditioning device 1 described above by a program executed by the CPU 101 .

[0052] Battery B is mounted on the EV. Battery B is charged by connecting a charger plug PS to battery plug BP, and power is supplied to vehicle air conditioner 1 via battery B. When plug PS is connected to battery plug BP, a charger connection signal is transmitted to control device 100 via vehicle network L.

[0053] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the specific structure is not limited to these embodiments, and even if there are design changes within the scope of the gist of the present invention, they are also included in the present invention. In addition, as long as there are no special contradictions or problems in the purposes and structures of the above-mentioned embodiments, the technologies of each other can be used for combination. Description of Reference Numerals

[0054] 1: Vehicle air conditioning device, 2: Compressor, 3: Notification device (display device), 10: Refrigerant circuit, 10V: Hot gas bypass, 11: External heat exchanger, 12, 13: channel switching valve, 14, 15: check valve, 16: liquid reservoir, 20: air conditioning unit, 21, 22: indoor heat exchanger, 23: air blower, 30: heat medium circuit, 31: circulation pump, 32: heater, 33: Temperature control object heat exchanger, 34: Refrigerant heat medium heat exchanger, 24, 25: air doors, 25A, 25B: air inlets, 40: sensor unit, 41: outside air sensor, 42: compressor current sensor, 43: Refrigerant temperature sensor, 44: Refrigerant pressure sensor, 45: Passenger sensor, 46: Supply air temperature sensor, 100: control device, V1: first decompression section, V2: second decompression section, V3: fourth decompression section, V3: fourth decompression section.

Claims

1. A vehicle air conditioning device, comprising: A refrigerant circuit including a compressor, an indoor heat exchange section, an external heat exchange section and a refrigerant heat medium heat exchanger; a heat medium circuit for circulating the heat medium that exchanges heat with the refrigerant through the refrigerant-heat medium heat exchanger; an air conditioning unit, in which the indoor heat exchange portion is disposed; as well as A control device controls the refrigerant circuit, the heat medium circuit and the air conditioning unit, wherein: The refrigerant circuit includes a hot gas bypass that reduces the pressure of at least a portion of the refrigerant compressed by the compressor and returns to the compressor without passing through the indoor heat exchange part and the external heat exchange part. The control device can perform a hot air heating operation and a heat absorption heating operation. In the hot air heating operation, the refrigerant is not allowed to absorb heat in the external heat exchange part, but a part of the refrigerant compressed by the compressor is allowed to dissipate heat through the indoor heat exchange part to heat the vehicle interior. In the heat absorption heating operation, the refrigerant is allowed to absorb heat through the external heat exchange part. The control device determines whether it is necessary to recover the refrigerant from the external heat exchange part. When the control device determines that the refrigerant needs to be recovered, the control device performs a refrigerant recovery process of recovering the refrigerant from the external heat exchange unit after the previous air-conditioning operation is performed or before the hot air heating operation is performed.

2. The vehicle air conditioning device according to claim 1, wherein: In the refrigerant recovery process, the low-pressure flow path of the refrigerant circuit passes through the refrigerant-heat medium heat exchanger, and the downstream side of the external heat exchange portion is connected to the low-pressure flow path.

3. The vehicle air conditioning device according to claim 2, wherein: In the refrigerant recovery process, the hot gas bypass is closed to reduce the pressure of the low-pressure flow channel.

4. The vehicle air conditioning device according to claim 1, wherein: In the refrigerant recovery process, the flow of the refrigerant during the heat absorption heating operation is performed in a state where heat dissipation from the external heat exchange portion is suppressed.

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