Refrigerant extraction method for vehicle air conditioning device and vehicle air conditioning device

Abstract

To shorten a refrigerant recovery time from a refrigerant circuit.SOLUTION: A vehicle air conditioning device 1 includes an air conditioning part for performing air conditioning of a vehicle interior, a refrigerant adjustment part that is switchable between a first state in which a refrigerant is vaporized by decompression and a second state in which vaporization of the refrigerant by decompression is not performed, a compressor 11 that compresses the refrigerant and outputs the refrigerant, and an extraction port 20 that extracts the refrigerant to the outside of a refrigerant circuit 2. In a refrigerant recovery mode, a refrigerant extraction method includes: a refrigerant heating step in which the refrigerant adjustment part is set to the second state and the refrigerant output from the compressor is caused to pass through the air conditioning part and the refrigerant adjustment part in this order and then flow again into the compressor 11; and an extraction step in which the extraction port 20 is opened after the refrigerant heating step or during execution of the refrigerant heating step.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The technology disclosed herein belongs to the technical field relating to a refrigerant removal method for a vehicle air conditioner and a vehicle air conditioner. [Background technology]

[0002] 2. Description of the Related Art Vehicle air conditioners that use a refrigerant to condition the air inside a vehicle compartment have been known.

[0003] For example, in the vehicle air conditioning system described in Patent Document 1, in the cooling mode, the refrigerant output from the compressor is circulated through the heater core, the outdoor heat exchanger, the air conditioning valve, and the evaporator in that order, before flowing back into the compressor, and in the heating mode, the refrigerant output from the compressor is circulated through the heater core, the expansion valve, and the outdoor heat exchanger in that order, before flowing back into the compressor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-035104 Summary of the Invention [Problem to be solved by the invention]

[0005] When replacing the refrigerant in a vehicle air conditioner, it is necessary to drain all of the existing refrigerant from the refrigerant circuit. Conventionally, the refrigerant recovery process requires opening the outlet of the refrigerant circuit and reducing the pressure using an external device to recover the refrigerant, which takes a long time. Particularly in low-temperature environments where the heating mode is used, the refrigerant may be liquefied when the refrigerant is recovered. If the refrigerant is liquefied, the refrigerant circuit must be depressurized to the point where it vaporizes, which lengthens the recovery time.

[0006] The technique disclosed herein has been made in view of the above points, and its object is to shorten the time required to recover refrigerant from a refrigerant circuit. [Means for solving the problem]

[0007] To solve the above problems, a first aspect of the technology disclosed herein is directed to a refrigerant removal method for a vehicle air conditioner that conditions the air inside a vehicle cabin using a refrigerant circulating in a refrigerant circuit. The vehicle air conditioner includes an air conditioning unit for conditioning the air inside the vehicle cabin, a refrigerant adjustment unit that can switch between a first state in which the refrigerant is evaporated by reducing pressure and a second state in which the refrigerant is not evaporated by reducing pressure, a compressor that compresses the refrigerant and then outputs it, and an outlet for removing the refrigerant to the outside of the refrigerant circuit. In a cooling mode and a heating mode in which the refrigerant is used to condition the air in the vehicle cabin, the refrigerant adjustment unit is set to the first state, and the refrigerant output from the compressor passes through the air conditioning unit and the refrigerant adjustment unit, and then flows back into the compressor to circulate within the refrigerant circuit.In a refrigerant recovery mode in which the refrigerant is extracted from the refrigerant circuit, the refrigerant adjustment unit is set to the second state, and the refrigerant output from the compressor passes through the air conditioning unit and the refrigerant adjustment unit in that order, and then flows back into the compressor to circulate within the refrigerant circuit.The system includes a refrigerant heating step in which the refrigerant adjustment unit is set to the second state, and the refrigerant output from the compressor passes through the air conditioning unit and the refrigerant adjustment unit in that order, and then flows back into the compressor to circulate within the refrigerant circuit, and an extraction step in which the extraction port is opened after the refrigerant heating step or during execution of the refrigerant heating step.

[0008] In the first aspect, the refrigerant heating step circulates the refrigerant through the refrigerant circuit without vaporizing the refrigerant through pressure reduction, thereby increasing the temperature and pressure of the refrigerant within the refrigerant circuit. If the refrigerant temperature is high, the refrigerant can be vaporized without pressure reduction. Furthermore, by opening the outlet when the refrigerant temperature and pressure are high, the vaporized refrigerant can be efficiently discharged from the outlet. This shortens the refrigerant recovery time.

[0009] In this specification, the "second state in which the refrigerant is not vaporized by decompression" refers not only to a state in which all of the refrigerant is not vaporized by decompression, but also to a state in which only a small portion of the refrigerant is vaporized by decompression and the majority of the refrigerant is not vaporized by decompression.

[0010] In a second aspect, in the first aspect, the air conditioning unit has a heating heat exchanger and an evaporator, and the vehicle air conditioning device further includes a first switching unit that can switch between an open state in which the refrigerant passes through the evaporator and a closed state in which the refrigerant does not pass through the evaporator, and in a cooling mode, the first switching unit is set to the open state and the refrigerant adjustment unit is set to the first state, and the refrigerant output from the compressor passes through the heating heat exchanger, the refrigerant adjustment unit, and the evaporator in this order, and then flows into the compressor again. In the heating mode, the first switching unit is set to the closed state and the refrigerant adjustment unit is set to the first state, and the refrigerant output from the compressor passes through the heating heat exchanger and the refrigerant adjustment unit in that order, and then flows into the compressor again; in the refrigerant heating step of the refrigerant recovery mode, the first switching unit is set to the closed state and the refrigerant adjustment unit is set to the second state, and the refrigerant output from the compressor passes through the heating heat exchanger and the refrigerant adjustment unit in that order, and then flows into the compressor again.

[0011] In the second mode, the only difference between the refrigerant recovery mode and the heating mode is the state of the refrigerant adjustment unit. When it becomes necessary to extract refrigerant in a low-temperature environment where the heating mode is used, all that is required is to switch the refrigerant adjustment unit and perform the same operation as in the heating mode. This allows for easy refrigerant recovery.

[0012] A third aspect is the second aspect, wherein the refrigerant heating step includes a first circulation step in which the first switching unit is set to the closed state and the refrigerant adjustment unit is set to the second state, and the refrigerant output from the compressor passes through the heating heat exchanger and the refrigerant adjustment unit in that order, and then flows into the compressor again; and a second circulation step in which, after the first circulation step, the first switching unit is set to the open state and the refrigerant adjustment unit is set to the second state, and the refrigerant passes through the heating heat exchanger, the refrigerant adjustment unit, and the evaporator in that order, and then flows into the compressor again.

[0013] In the third aspect, by supplying high-temperature, high-pressure refrigerant to the path that supplies refrigerant to the evaporator, the refrigerant remaining in the path can be efficiently recovered, thereby shortening the time required to recover the refrigerant.

[0014] A fourth aspect is the third aspect, wherein the vehicle air conditioning system further includes a battery temperature adjustment unit located on a path in the refrigerant circuit branching off from a path from the heating heat exchanger to the evaporator, and adjusting the temperature of a battery that supplies power to an electric motor that generates driving force for the vehicle, and a second switching unit switchable between an open state in which the refrigerant passes through the battery temperature adjustment unit and a closed state in which the refrigerant does not pass through the battery temperature adjustment unit, and in the first circulation step and the second circulation step, the second switching unit is set to the closed state, and the refrigerant heating step further includes a third circulation step in which, after the first circulation step, the first switching unit is set to the closed state, the second switching unit is set to the open state, and the refrigerant adjustment unit is set to the second state, and the refrigerant passes through the heating heat exchanger, the refrigerant adjustment unit, and the battery temperature adjustment unit in that order, and then flows into the compressor again.

[0015] In the fourth aspect, by supplying a high-temperature, high-pressure refrigerant to the path that supplies the refrigerant to the battery temperature adjustment unit, the refrigerant remaining in the path can be efficiently recovered, thereby shortening the time required to recover the refrigerant.

[0016] In a fifth aspect, in the third aspect, the vehicle air conditioning device further includes a battery temperature adjustment unit that adjusts the temperature of a battery located in a path branching from the path from the heating heat exchanger to the evaporator in the refrigerant circuit and that supplies power to an electric motor that generates driving force for the vehicle, and the refrigerant adjustment unit has an expansion valve that is provided in the battery temperature adjustment unit and has an adjustable opening, and in the cooling mode and the heating mode, the expansion valve is opened to an opening that allows the refrigerant to evaporate, while in the first circulation step of the refrigerant recovery mode, the expansion valve is opened to an opening that does not allow the refrigerant to evaporate, and in the second circulation step of the refrigerant recovery mode, the expansion valve is fully closed.

[0017] In the fifth aspect, the refrigerant remaining in the path supplying the refrigerant to the battery temperature adjustment unit can be heated to a high temperature and a high pressure in the first circulation step, thereby shortening the time required to recover the refrigerant.

[0018] A sixth aspect is any one of the third to fifth aspects, wherein the vehicle air conditioning system further includes a temperature sensor that detects the refrigerant temperature in the refrigerant circuit and a pressure sensor that detects the refrigerant pressure in the refrigerant circuit, and transitions to the second circulation step when at least one of the following is satisfied: the refrigerant temperature detected by the temperature sensor in the first circulation step is equal to or higher than a first predetermined temperature; and the refrigerant pressure detected by the pressure sensor in the first circulation step is equal to or higher than a first predetermined pressure.

[0019] In the sixth aspect, the second circulation step is started when at least one of the temperature and pressure of the refrigerant in the refrigerant circuit is sufficiently high, so that the refrigerant remaining in the path supplying the refrigerant to the evaporator can be efficiently recovered, thereby shortening the time required to recover the refrigerant.

[0020] In a seventh aspect, in the sixth aspect, when at least one of the following conditions is satisfied: the refrigerant temperature detected by the temperature sensor is a second predetermined temperature higher than the first predetermined temperature; and the refrigerant pressure detected by the pressure sensor is a second predetermined pressure higher than the first predetermined pressure, the process transitions from the refrigerant heating step to the removing step.

[0021] In the seventh aspect, when the refrigerant temperature reaches a second predetermined temperature higher than the first predetermined temperature, or when the refrigerant pressure reaches a second predetermined pressure higher than the first predetermined pressure, it can be determined that all of the refrigerant in the refrigerant circuit has vaporized. By proceeding to the extraction step in this state, the refrigerant can be efficiently extracted. This shortens the refrigerant recovery time.

[0022] The eighth aspect is directed to a vehicle air conditioner that conditions the air inside a vehicle compartment using a refrigerant that circulates through a refrigerant circuit. The vehicle air conditioner includes an air conditioning unit for conditioning the air in the vehicle cabin, a refrigerant adjustment unit that can be changed between a first state in which the refrigerant is evaporated by reducing pressure and a second state in which the refrigerant is not evaporated by reducing pressure, a compressor that compresses the refrigerant and then outputs it, an outlet for removing the refrigerant from the refrigerant circuit, and a controller. In a cooling mode and a heating mode in which the air conditioning in the vehicle cabin is performed using the refrigerant, the controller sets the refrigerant adjustment unit to the first state, and causes the refrigerant output from the compressor to pass through the air conditioning unit and the refrigerant adjustment unit, and then flows back into the compressor to circulate within the refrigerant circuit. In a refrigerant recovery mode in which the refrigerant is removed from the refrigerant circuit, the controller sets the refrigerant adjustment unit to the second state before the outlet is opened, and causes the refrigerant output from the compressor to pass through the air conditioning unit and the refrigerant adjustment unit, and then flows back into the compressor to circulate within the refrigerant circuit.

[0023] In the eighth aspect, in the refrigerant recovery mode, the refrigerant is circulated through the refrigerant circuit without being vaporized by reducing the pressure, thereby increasing the temperature and pressure of the refrigerant within the refrigerant circuit. Then, by opening the outlet while the refrigerant temperature and pressure are high, the vaporized refrigerant can be efficiently discharged from the outlet. This shortens the refrigerant recovery time.

[0024] A ninth aspect is the eighth aspect, wherein the outlet is provided downstream of the air conditioning unit.

[0025] In the ninth aspect, the refrigerant pressure is lower at a position downstream of the air conditioning unit in the refrigerant circuit than immediately after the compressor. Because the refrigerant flows from the high-pressure side to the low-pressure side in the refrigerant circuit, if the outlet is located at a position where the refrigerant pressure is low, the refrigerant can be efficiently recovered. This shortens the refrigerant recovery time. [Effects of the Invention]

[0026] As described above, the technique disclosed herein can shorten the time required to recover refrigerant from the refrigerant circuit. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a schematic diagram showing a vehicle air conditioning system according to a first exemplary embodiment. [Figure 2] FIG. 2 is a block diagram showing a control system of the vehicle air conditioner. [Figure 3] FIG. 3 is an explanatory diagram showing the refrigerant path in the cooling mode of the vehicle air conditioner. [Figure 4] FIG. 4 is an explanatory diagram showing the refrigerant path in the heating mode of the vehicle air conditioner. [Figure 5] FIG. 5 is an explanatory diagram showing the refrigerant paths in the first refrigerant heating mode of the vehicle air conditioner. [Figure 6] FIG. 6 is an explanatory diagram showing the refrigerant path in the second refrigerant heating mode of the vehicle air conditioner. [Figure 7]FIG. 7 is an explanatory diagram showing the refrigerant path in the vehicle air conditioner in the third refrigerant heating mode. [Figure 8] FIG. 8 is a flowchart showing a method for removing refrigerant from an air conditioner for a vehicle. [Figure 9] FIG. 9 is a schematic diagram showing a refrigerant circuit of a vehicle air conditioner according to the second embodiment. [Figure 10] FIG. 10 is a block diagram showing a control system of a vehicle air conditioner according to the second embodiment. [Figure 11] FIG. 11 is an explanatory diagram showing the refrigerant path in the cooling mode of the vehicle air conditioner according to the second embodiment. [Figure 12] FIG. 12 is an explanatory diagram showing the refrigerant paths in the heating mode of the vehicle air conditioner according to the second embodiment. [Figure 13] FIG. 13 is an explanatory diagram showing the refrigerant paths in the second refrigerant heating mode of the vehicle air conditioner according to the second embodiment. [Figure 14] FIG. 14 is a flowchart showing a refrigerant removal method for a vehicle air conditioner according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, the first exemplary embodiment will be described in detail with reference to the drawings.

[0029] First Embodiment (1) Overall configuration of a vehicle air conditioning system FIG. 1 schematically shows a vehicle air conditioner 1 (hereinafter referred to as "air conditioner 1"). The air conditioner 1 conditions the air inside the vehicle cabin using a refrigerant in response to an air conditioning request from a vehicle occupant. The air conditioner 1 is a heat pump type air conditioner. The air conditioner 1 is mounted on, for example, an electric vehicle that can run using driving force generated by an electric motor 4 as an electric motor. The refrigerant is, for example, an HFO (hydrofluoroolefin) refrigerant, specifically R1234yf, R134a, R744, R290, etc.

[0030] The air conditioner 1 includes a refrigerant circuit 2. The refrigerant circuit 2 includes a compressor 11, an indoor heat exchanger 12, a two-way valve 13, an orifice 14, an outdoor heat exchanger 15, a three-way valve 16, an air conditioning expansion valve 21, an evaporator 17, a battery expansion valve 22, a battery heat exchanger 18, and an accumulator 19.

[0031] The compressor 11 compresses and outputs the refrigerant. Various types of compressors can be used for the compressor 11. For example, the compressor 11 is a scroll compressor or a rotary compressor. The compressor 11 has a motor (not shown). The motor operates by receiving power from a battery 3 that supplies power to an electric motor M.

[0032] The interior heat exchanger 12 is a heat exchanger that dissipates heat into the air for air conditioning sent into the vehicle interior in the heating mode. The interior heat exchanger 12 constitutes an air conditioning unit.

[0033] The two-way valve 13 and the orifice 14 are arranged in parallel. In the cooling mode and the refrigerant recovery mode, the two-way valve 13 is opened, and the refrigerant passes through the two-way valve 13. When the two-way valve 13 is opened, almost no fluid pressure is applied to the orifice 14, and the refrigerant does not pass through the orifice 14. In the heating mode, the two-way valve 13 is closed. When the two-way valve 13 is closed, fluid pressure is applied to the orifice 14, and the refrigerant passes through the orifice 14. When the refrigerant passes through the orifice 14, the refrigerant vaporizes due to the pressure change. The two-way valve 13 and the orifice 14 constitute a refrigerant adjustment unit.

[0034] The exterior heat exchanger 15 is a heat exchanger that exchanges heat between the air taken in from outside the vehicle and the refrigerant. The exterior heat exchanger 15 exchanges heat with the air blown from the radiator fan 15a and the airflow caused by the vehicle traveling introduced through the grille shutter 15b. The volume of the air blown from the radiator fan 15a is adjusted by the rotation speed of the radiator fan 15a. The volume of the airflow caused by the vehicle traveling supplied to the exterior heat exchanger 15 is adjusted by the opening degree of the grille shutter 15b.

[0035] The three-way valve 16 is a switching valve for sending the refrigerant output from the outdoor heat exchanger 15 to either the cooling pipe 2a or the heating pipe 2b.

[0036] The air conditioning expansion valve 21 and the evaporator 17 are arranged in the cooling pipe 2a. The air conditioning expansion valve 21 is an electromagnetic expansion valve that can linearly adjust the flow rate. When fully open, the air conditioning expansion valve 21 functions as a simple passage, allowing the refrigerant to pass through without decompressing it. When fully closed, the air conditioning expansion valve 21 closes the passage and does not allow the refrigerant to pass through. When the air conditioning expansion valve 21 is fully closed, the refrigerant is not vaporized by the air conditioning expansion valve 21. When the air conditioning expansion valve 21 is open between the fully open and fully closed states, it decompresses and vaporizes the refrigerant depending on its opening. The evaporator 17 is a heat exchanger that, in cooling mode, exchanges heat (absorbs heat) between the refrigerant vaporized by the air conditioning expansion valve 21 and the air for air conditioning. The evaporator 17 cools the air for air conditioning by the heat absorption effect of the vaporized refrigerant. The heating pipe 2b merges with the cooling pipe 2a upstream of the accumulator 19. The air conditioning expansion valve 21 constitutes a refrigerant adjustment unit and a first switching unit. The evaporator 17 constitutes an air conditioning unit.

[0037] The indoor heat exchanger 12 and the evaporator 17 are arranged in an air flow path for air conditioning (not shown). A blower fan 5 is arranged in the air flow path. The blower fan 5 blows air for air conditioning toward the evaporator 17. An air mix damper (not shown) is arranged in the air flow path. The air mix damper switches whether or not the air for air conditioning that has passed through the evaporator 17 passes through the indoor heat exchanger 12. In the cooling mode, the air mix damper switches so that the air for air conditioning does not pass through the indoor heat exchanger 12, and in the heating mode, it switches so that the air for air conditioning passes through the indoor heat exchanger 12.

[0038] The battery-side expansion valve 22 and the battery heat exchanger 18 are disposed in the battery pipe 2c. The battery pipe 2c is a pipe branched from the air conditioning pipe 2a. That is, the battery pipe 2c constitutes a path branched from the path from the indoor heat exchanger 12 to the evaporator 17. The battery-side expansion valve 22 is disposed in the battery pipe 2c at a position upstream of the battery heat exchanger 18. The battery-side expansion valve 22 is an electromagnetic expansion valve that can linearly adjust the flow rate. In a fully open state, the battery-side expansion valve 22 functions as a simple passage, allowing the refrigerant to pass without reducing its pressure. In a fully closed state, the battery-side expansion valve 22 closes the passage, preventing the refrigerant from passing. When the battery-side expansion valve 22 is in a fully closed state, the battery-side expansion valve 22 does not vaporize the refrigerant. When the battery-side expansion valve 22 is open between a fully open state and a fully closed state, it reduces the pressure of the refrigerant and vaporizes it according to its opening degree. The battery heat exchanger 18 is configured to directly exchange heat between the battery 3 and the refrigerant without using an intermediate medium (such as water). The battery pipe 2c merges with the air conditioning pipe 2a downstream of the battery heat exchanger 18. The battery-side expansion valve 22 constitutes a refrigerant adjustment unit and a second switching unit. The battery heat exchanger 18 corresponds to a battery temperature adjustment unit.

[0039] The accumulator 19 is disposed before the compressor 11. The refrigerant that has passed through the cooling pipe 2a and the heating pipe 2b flows into the compressor 11 again via the accumulator 19.

[0040] The refrigerant circuit 2 has an outlet 20 downstream of the junction of the cooling pipe 2a and the heating pipe 2b and upstream of the accumulator 19. The outlet 20 is an opening for extracting refrigerant from the refrigerant circuit 2. The outlet 20 is normally closed. The outlet 20 is opened when refrigerant is to be extracted from the refrigerant circuit 2.

[0041] The refrigerant circuit 2 is provided with a plurality of sensors that detect the state of the refrigerant flowing through the circuit. The plurality of sensors includes a first temperature sensor ST1, a second temperature sensor ST2, a third temperature sensor ST3, a fourth temperature sensor ST4, a first pressure sensor SP1, and a second pressure sensor SP2.

[0042] The first temperature sensor ST1 is disposed in the refrigerant circuit 2 at a position downstream of the compressor 11 and upstream of the indoor heat exchanger 12. The first temperature sensor ST1 detects the temperature of the refrigerant immediately after it is output from the compressor 11.

[0043] The second temperature sensor ST2 is disposed in the refrigerant circuit 2 at a position downstream of the exterior heat exchanger 15 and upstream of the three-way valve 16. The second temperature sensor ST2 detects the temperature of the refrigerant after heat exchange with the air outside the vehicle by the exterior heat exchanger 15.

[0044] The third temperature sensor ST3 is disposed in the cooling pipe 2a downstream of the evaporator 17 and upstream of the junction with the battery pipe 2c. The third temperature sensor ST3 detects the temperature of the refrigerant after heat exchange with the air for air conditioning by the evaporator 17.

[0045] The fourth temperature sensor ST4 is disposed in the battery pipe 2c downstream of the battery heat exchanger 18 and upstream of the junction with the air conditioning pipe 2a. The fourth temperature sensor ST4 detects the temperature of the refrigerant after heat exchange with the battery 3 by the battery heat exchanger 18.

[0046] The first pressure sensor SP1 is disposed in the refrigerant circuit 2 at a position downstream of the indoor heat exchanger 12 and upstream of the two-way valve 13 and the orifice 14. The first pressure sensor SP1 detects the pressure of the refrigerant immediately before passing through the two-way valve 13 or the orifice 14.

[0047] The second pressure sensor SP2 is disposed in the battery pipe 2c downstream of the battery heat exchanger 18 and upstream of the junction with the air conditioning pipe 2a. The second pressure sensor SP2 detects the pressure of the refrigerant after heat exchange with the battery 3 by the battery heat exchanger 18.

[0048] (2) Vehicle air conditioning control system The air conditioner 1 is controlled by a controller 100. The controller 100 may be configured with a single ECU (Electrical Control Unit) or multiple ECUs. The ECU that constitutes the controller 100 is a controller based on a well-known microcomputer and includes a central processing unit (CPU), a memory, and an I / F circuit. The CPU executes programs. The memory is configured with, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory) and stores programs and data. The I / F circuit inputs and outputs electrical signals.

[0049] 2, an external command ES and signals from the temperature sensors ST1 to ST4 and the pressure sensors SP1 and SP2 are input to the controller 100. The external command ES is a cooling request, a heating request, a request to change the air conditioning temperature, etc. The external command ES also includes a refrigerant recovery request to recover refrigerant from the refrigerant circuit 2.

[0050] The controller 100 determines the operating state of the air conditioner 1 based on the external command ES and signals from the temperature sensors ST1 to ST4 and the pressure sensors SP1 and SP2, and calculates the control amount of each device according to a predetermined control logic. The control logic is stored in the memory 102. The control logic includes calculating the target amount and the control amount using maps and arithmetic expressions stored in the memory 102.

[0051] The controller 100 outputs electrical signals related to the calculated control amounts to the compressor 11, the two-way valve 13, the three-way valve 16, the air conditioning side expansion valve 21, the battery side expansion valve 22, the radiator fan 15a, and the grill shutter 15b.

[0052] (3) Cooling mode When there is a request for cooling, the controller 100 switches the refrigerant circuit 2 to cooling mode and circulates the refrigerant. Figure 3 shows the refrigerant flow path in cooling mode. Figure 3 also shows the refrigerant flow path when there is a request for battery cooling in cooling mode.

[0053] In the cooling mode, the two-way valve 13 is open. In the refrigerant mode, the three-way valve 16 is switched to the cooling pipe 2a side. In the refrigerant mode, the air conditioning expansion valve 21 is adjusted to an opening degree that evaporates the refrigerant by reducing the pressure. Furthermore, when there is a request for battery cooling, the battery expansion valve 22 is adjusted to an opening degree that evaporates the refrigerant by reducing the pressure. In the cooling mode, the refrigerant is evaporated by the air conditioning expansion valve 21, so the refrigerant adjustment unit can be said to be in a first state in which the refrigerant is evaporated by reducing the pressure.

[0054] The refrigerant is compressed by a compressor 11 and passes in the form of a high-pressure gas through an indoor heat exchanger 12. The refrigerant does not pass through an orifice 14, but passes through a two-way valve 13 and then through an outdoor heat exchanger 15. In the outdoor heat exchanger 15, the refrigerant releases heat to the air outside the vehicle and is liquefied.

[0055] In the cooling pipe 2a, the refrigerant is vaporized by reducing the pressure by the air conditioning expansion valve 21. The vaporized refrigerant passes through the evaporator 17, where it absorbs heat from the air for air conditioning.

[0056] A portion of the refrigerant that has flowed into the air conditioning pipe 2a flows into the battery pipe 2c. In the battery pipe 2c, the refrigerant is decompressed and vaporized by the battery-side expansion valve 22. The vaporized refrigerant passes through the battery heat exchanger 18 and absorbs heat from the battery 3 in the battery heat exchanger 18.

[0057] The refrigerant that has passed through the cooling pipe 2a and the battery pipe 2c passes through the accumulator 19, and then flows into the compressor 11 again as a low-pressure gas.

[0058] In the cooling mode, the refrigerant circulates through the refrigerant circuit 2 as described above. When there is no demand for battery cooling in the cooling mode, the battery-side expansion valve 22 is fully closed. The refrigerant does not flow into the battery pipe 2c, but passes through the air conditioning-side expansion valve 21 and flows into the evaporator 17.

[0059] (4) Heating mode When there is a request for heating, the controller 100 switches the refrigerant circuit 2 to heating mode and circulates the refrigerant. Figure 4 shows the refrigerant flow path in heating mode. Figure 4 also shows the refrigerant flow path when there is no request for battery cooling in heating mode.

[0060] In the heating mode, the two-way valve 13 is closed. In the heating mode, the three-way valve 16 is switched to the heating pipe 2b side. In the heating mode, the air conditioning side expansion valve 21 is fully closed. Furthermore, if there is no demand for battery cooling, the battery side expansion valve 22 is fully closed. In the heating mode, the refrigerant is vaporized by the orifice 14, so the refrigerant adjustment unit can be said to be in a first state in which the refrigerant is vaporized by reducing the pressure.

[0061] The refrigerant is compressed by the compressor 11 and passes through the indoor heat exchanger 12 in the state of a high-pressure gas. The refrigerant releases heat in the indoor heat exchanger 12 and is liquefied. The refrigerant passes through the orifice 14 without passing through the two-way valve 13. The refrigerant is reduced in pressure by the orifice 14 and vaporizes. The vaporized refrigerant passes through the outdoor heat exchanger 15. The refrigerant absorbs heat from the air outside the vehicle in the outdoor heat exchanger 15. After flowing into the heating pipe 2b, the refrigerant passes through the accumulator 19 and flows back into the compressor 11 as a low-pressure gas.

[0062] In the heating mode, the refrigerant circulates through the refrigerant circuit 2 as described above. When a battery cooling request is made during the heating mode, the two-way valve 13 is switched to an open state, and the three-way valve 16 is switched to the cooling pipe 2a side. The battery-side expansion valve 22 is adjusted to an opening degree that vaporizes the refrigerant by reducing the pressure. When the battery cooling request is canceled, the two-way valve 13 and the three-way valve 16 are switched to the heating mode state described above, and the battery-side expansion valve 22 is fully closed.

[0063] (5) Refrigerant recovery mode In the first embodiment, when the air conditioner 1 fails or when the refrigerant needs to be replaced, the controller 100 sets the refrigerant circuit 2 to a refrigerant recovery mode for removing the refrigerant from the refrigerant circuit 2. The controller 100 executes the refrigerant recovery mode when a request signal is input by an operator who is removing the refrigerant. The refrigerant recovery mode is a mode that is executed when the vehicle is stopped, and is not executed while the vehicle is running.

[0064] The refrigerant recovery mode is a mode for vaporizing all of the refrigerant in the refrigerant circuit 2 and for making the refrigerant easier to remove from the refrigerant circuit by increasing the pressure. In the first embodiment, the refrigerant recovery mode includes a first circulation step, a second circulation step, a third circulation step, and a removal step. The first circulation step, the second circulation step, and the third circulation step correspond to a refrigerant heating step.

[0065] (5-1) First circulation step FIG. 5 shows the refrigerant circulation path in the first circulation step. In the first circulation step, the two-way valve 13 is in an open state. In the first circulation step, the three-way valve 16 is switched to the heating pipe 2b side. In the first circulation step, the air conditioning side expansion valve 21 and the battery side expansion valve 22 are both in a fully closed state. In this way, the circulation path in the first circulation step is the same as the circulation path in the heating mode, except that the two-way valve 13 is in an open state. In the first circulation step, the refrigerant does not evaporate due to reduced pressure, so the refrigerant adjustment unit can be said to be in a second state in which refrigerant evaporation due to reduced pressure is not performed.

[0066] The refrigerant is compressed by compressor 11 and passes through indoor heat exchanger 12 in the state of high-pressure gas, then passes through two-way valve 13 without passing through orifice 14. The refrigerant then passes through outdoor heat exchanger 15 and flows into heating pipe 2b. The refrigerant passes through accumulator 19 via heating pipe 2b and then flows into compressor 11 again.

[0067] In the first circulation step, the refrigerant is circulated through the shortest circulation path without being decompressed. As the refrigerant continues to be compressed by compressor 11, its temperature gradually increases. As a result, even if the refrigerant is not vaporized by decompression, it will vaporize by reaching a high temperature. In the first circulation step, circulating the refrigerant through the shortest circulation path allows the refrigerant to be efficiently brought to a high temperature and high pressure state. As mentioned above, the refrigerant recovery mode is a mode that is executed while the vehicle is stopped, so even if the refrigerant passes through indoor heat exchanger 12 and outdoor heat exchanger 15, the refrigerant hardly releases heat.

[0068] (5-2) Second circulation step FIG. 6 shows the refrigerant circulation path in the second circulation step. The second circulation step is a step for vaporizing the refrigerant remaining in the cooling pipe 2a. The second circulation step is performed after the first circulation step. The second circulation step may be performed before or after the third circulation step. The timing of transitioning from the first or third circulation step to the second circulation step is determined by the detection values ​​of the first temperature sensor ST1 and the first pressure sensor SP1. Specifically, transition to the second circulation step occurs when the detection value of the first temperature sensor ST1 becomes equal to or greater than a first predetermined temperature Tc1 or the detection value of the first pressure sensor SP1 becomes equal to or greater than a first predetermined pressure Pc1. Note that the timing of transitioning to the second circulation step may also be determined by the detection values ​​of other temperature sensors and pressure sensors provided in the path through which the refrigerant circulated in the immediately preceding circulation step. In particular, when transitioning from the third circulation step to the second circulation step, the timing of transition to the second circulation step may be determined based on the detection value of the fourth temperature sensor ST4 and the detection value of the second pressure sensor SP2.

[0069] In the second circulation step, the two-way valve 13 is in an open state and a closed state. In the second circulation step, the three-way valve 16 is switched to the cooling pipe 2a side. In the second circulation step, the air conditioning side expansion valve 21 is in a fully open state, and the battery side expansion valve 22 is in a fully closed state. In the second circulation step, the refrigerant does not evaporate due to pressure reduction, so the refrigerant adjustment unit can be said to be in a second state in which refrigerant evaporation due to pressure reduction is not performed.

[0070] The refrigerant is compressed by the compressor 11 and passes through the indoor heat exchanger 12 in the state of a high-pressure gas, and then passes through the two-way valve 13 without passing through the orifice 14. The refrigerant then passes through the outdoor heat exchanger 15 and flows into the cooling pipe 2a. In the cooling pipe 2a, the refrigerant passes through the air conditioning expansion valve 21 without being decompressed, and then passes through the evaporator 17. The refrigerant then passes through the accumulator 19 and flows into the compressor 11 again.

[0071] In the second circulation step, the refrigerant is circulated through the cooling pipe 2a without being decompressed. As a result, even if the refrigerant is present in the cooling pipe 2a, the refrigerant in the cooling pipe 2a can be brought to a high temperature and high pressure state. In particular, even if the refrigerant is present in the cooling pipe 2a in a liquid state, the refrigerant can be completely vaporized.

[0072] (5-3) Third circulation step FIG. 7 shows the refrigerant flow path in the third circulation step. The third circulation step is a step for vaporizing the refrigerant remaining in the battery pipe 2c. The third circulation step is performed after the first circulation step. The third circulation step may be performed before or after the second circulation step. The timing of transition from the first or second circulation step to the third circulation step is determined by the detection value of the first temperature sensor ST1 and the detection value of the first pressure sensor SP1. Specifically, transition to the third circulation step occurs when the detection value of the first temperature sensor ST1 becomes equal to or higher than a third predetermined temperature Tc3 or when the detection value of the first pressure sensor SP1 becomes equal to or higher than a third predetermined pressure Pc3. The third predetermined temperature Tc3 may be the same as or different from the first predetermined temperature Tc1. The third predetermined pressure Pc3 may be the same as or different from the third predetermined pressure Pc3. The timing of transition to the third circulation step may be determined based on the detected value of another temperature sensor and pressure sensor provided in the path through which the refrigerant flows in the immediately preceding circulation step. In particular, when transitioning from the second circulation step to the third circulation step, the timing of transition to the third circulation step may be determined based on the detected value of the third temperature sensor ST3.

[0073] In the third circulation step, the two-way valve 13 is in an open state. In the third circulation step, the three-way valve 16 is switched to the cooling pipe 2a side. In the third circulation step, the air conditioning side expansion valve 21 is in a fully closed state, and the battery side expansion valve 22 is in a fully open state. In the third circulation step, the refrigerant does not evaporate due to pressure reduction, so the refrigerant adjustment unit can be said to be in a second state in which refrigerant evaporation by pressure reduction is not performed.

[0074] The refrigerant is compressed by the compressor 11 and passes through the indoor heat exchanger 12 in the state of a high-pressure gas, and then passes through the two-way valve 13 without passing through the orifice 14. The refrigerant then passes through the outdoor heat exchanger 15 and flows into the air conditioning pipe 2a. The refrigerant passes through a part of the air conditioning pipe 2a and then flows into the battery pipe 2c. In the battery pipe 2c, the refrigerant passes through the battery-side expansion valve 22 without being decompressed, and then passes through the battery heat exchanger 18. The refrigerant then passes through the accumulator 19 and flows into the compressor 11 again.

[0075] In the third circulation step, the refrigerant is circulated through the battery pipe 2c without being decompressed. This allows the refrigerant in the battery pipe 2c to be kept at a high temperature and high pressure, even if the refrigerant is present in the battery pipe 2c. In particular, even if the refrigerant is present in the battery pipe 2c in a liquid state, the refrigerant can be completely vaporized.

[0076] (5-4) Removal step The extraction step is a process of extracting the refrigerant from the refrigerant circuit 2. The extraction step is performed after the second circulation step and the third circulation step are completed. The timing of transition from the second circulation step or the third circulation step to the extraction step is determined by the detection value of the first temperature sensor ST1 and the detection value of the first pressure sensor SP1. Specifically, transition to the extraction step occurs when the detection value of the first temperature sensor ST1 becomes equal to or higher than a second predetermined temperature Tc2 or the detection value of the first pressure sensor SP1 becomes equal to or higher than a second predetermined pressure Pc2. The second predetermined temperature Tc2 is a temperature higher than the first predetermined temperature Tc1 and the third predetermined temperature Tc3. The second predetermined pressure Pc2 is a pressure higher than the first predetermined pressure Pc1 and the third predetermined pressure Pc3. The timing of transition to the extraction step may also be determined by the detection values ​​of other temperature sensors and pressure sensors provided in the path through which the refrigerant circulated in the immediately preceding circulation step. In particular, the transition from the second circulation step to the removal step may be determined based on the detection value of the third temperature sensor ST3. Also, the transition from the third circulation step to the removal step may be determined based on the detection values ​​of the fourth temperature sensor ST4 and the second pressure sensor SP2.

[0077] In the extraction step, all valves are opened. Specifically, the two-way valve 13 is open, and the air conditioning expansion valve 21 and the battery expansion valve 22 are both fully open. The three-way valve 16 is switched to the cooling pipe 2a side. The compressor 11 is stopped.

[0078] After all the valves are opened and the compressor 11 is stopped, the outlet 20 is opened. The outlet 20 is manually opened by an operator. Because the refrigerant in the refrigerant circuit 2 is at high temperature and high pressure, the refrigerant is efficiently discharged from the outlet 20 even when the compressor 11 is stopped. Note that, to reliably discharge the refrigerant from the refrigerant circuit 2, a vacuum pump may be connected to the outlet 20 to suck out the refrigerant.

[0079] (6) Flowchart Next, the processing of the controller 100 in the refrigerant recovery mode will be described with reference to Fig. 8. In the following description, the compressor 11 is operating unless otherwise specified.

[0080] First, in step S101, the controller 100 determines whether or not a refrigerant recovery mode command has been issued. If the result is YES, that is, the controller 100 proceeds to step S102. On the other hand, if the result is NO, that is, the controller 100 has not issued a refrigerant recovery mode command, the controller 100 ends the process.

[0081] In step S102, the controller 100 performs a first circulation step. The controller 100 opens the two-way valve 13, switches the three-way valve 16 to the heating pipe 2b side, fully closes the air conditioning expansion valve 21, and fully closes the battery expansion valve 22.

[0082] Next, in step S103, the controller 100 determines whether the detection value T of the first temperature sensor ST1 is equal to or greater than the first predetermined temperature Tc1. If the result is YES, that is, the detection value T of the first temperature sensor ST1 is equal to or greater than the first predetermined temperature Tc1, the controller 100 proceeds to step S105. On the other hand, if the detection value T of the first temperature sensor ST1 is less than the first predetermined temperature Tc1, that is, NO, the controller 100 proceeds to step S104.

[0083] In step S104, the controller 100 determines whether the detection value P of the first pressure sensor SP1 is equal to or greater than the first predetermined pressure Pc1. If the detection value P of the first pressure sensor SP1 is equal to or greater than the first predetermined pressure Pc1 (YES), the controller 100 proceeds to step S105. On the other hand, if the detection value P of the first pressure sensor SP1 is less than the first predetermined pressure Pc1 (NO), the controller 100 returns to step S103.

[0084] In step S105, the controller 100 performs a second circulation step in which the controller 100 opens the two-way valve 13, switches the three-way valve 16 to the cooling pipe 2a side, fully opens the air conditioning expansion valve 21, and fully closes the battery expansion valve 22.

[0085] Next, in step S106, the controller 100 determines whether the detection value T of the first temperature sensor ST1 is equal to or greater than the third predetermined temperature Tc3. If the result is YES, that is, the detection value T of the first temperature sensor ST1 is equal to or greater than the third predetermined temperature Tc3, the controller 100 proceeds to step S108. On the other hand, if the detection value T of the first temperature sensor ST1 is less than the third predetermined temperature Tc3, that is, NO, the controller 100 proceeds to step S107.

[0086] In step S107, the controller 100 determines whether the detection value P of the first pressure sensor SP1 is equal to or greater than the third predetermined pressure Pc3. If the detection value P of the first pressure sensor SP1 is equal to or greater than the third predetermined pressure Pc3 (YES), the controller 100 proceeds to step S108. On the other hand, if the detection value P of the first pressure sensor SP1 is less than the third predetermined pressure Pc3 (NO), the controller 100 returns to step S106.

[0087] In step S108, the controller 100 performs a third circulation step in which the controller 100 opens the two-way valve 13, switches the three-way valve 16 to the cooling pipe 2a side, fully closes the air conditioning expansion valve 21, and fully opens the battery expansion valve 22.

[0088] Next, in step S109, the controller 100 determines whether the detection value T of the first temperature sensor ST1 is equal to or greater than the second predetermined temperature Tc2. If the result is YES, that is, the detection value T of the first temperature sensor ST1 is equal to or greater than the second predetermined temperature Tc2, the controller 100 proceeds to step S111. On the other hand, if the result is NO, that is, the detection value T of the first temperature sensor ST1 is less than the second predetermined temperature Tc2, the controller 100 proceeds to step S110.

[0089] In step S110, the controller 100 determines whether the detection value P of the first pressure sensor SP1 is equal to or greater than the second predetermined pressure Pc2. If the result is YES, that is, the detection value P of the first pressure sensor SP1 is equal to or greater than the second predetermined pressure Pc2, the controller 100 proceeds to step S108. On the other hand, if the result is NO, that is, the detection value P of the first pressure sensor SP1 is less than the second predetermined pressure Pc2, the controller 100 returns to step S106.

[0090] In step S111, the controller 100 performs the extraction step. The controller 100 opens the two-way valve 13, switches the three-way valve 16 to the cooling pipe 2a side, fully opens the air conditioning expansion valve 21, and fully opens the battery expansion valve 22. The controller 100 also stops the compressor 11. After step S111, the controller 100 ends the processing.

[0091] After the compressor 11 is stopped in step S111, the outlet 20 is opened by an operator, and the refrigerant is taken out of the refrigerant circuit 2.

[0092] The order of the second circulation step and the third circulation step may be reversed, i.e., the third circulation step may be executed in step S105, and the second circulation step may be executed in step S108.

[0093] (7) Effects of the First Embodiment Therefore, in the refrigerant recovery mode in which the refrigerant is extracted from the refrigerant circuit 2, a refrigerant heating step (steps S102, 105, 108) is performed in which the refrigerant output from the compressor 11 is circulated within the refrigerant circuit 2 without vaporizing the refrigerant by reducing the pressure within the refrigerant circuit 2, and a removal step (step S111) is performed after the refrigerant heating step in which the outlet 20 is opened. The refrigerant heating step circulates the refrigerant within the refrigerant circuit 2 without vaporizing the refrigerant by reducing the pressure, thereby increasing the temperature and pressure of the refrigerant within the refrigerant circuit 2. If the refrigerant temperature is increased, the refrigerant can be vaporized without reducing the pressure. Furthermore, by opening the outlet 20 when the refrigerant temperature and pressure are high, the vaporized refrigerant can be quickly discharged from the outlet 20, allowing the refrigerant to be efficiently recovered. This shortens the refrigerant recovery time.

[0094] In particular, in environments where the outside air temperature is low (winter or cold regions), the refrigerant is in a low-temperature and low-pressure state, and it takes a long time to recover the refrigerant even if a vacuum suction device or the like is connected to the outlet 20. Furthermore, in environments where the outside air temperature is low, the refrigerant may liquefy in the refrigerant circuit 2. In such cases, it is necessary to continue removing the refrigerant until all of the refrigerant has evaporated, which is particularly time-consuming. In the first embodiment, the refrigerant can be kept in a high-temperature and high-pressure state in the refrigerant circuit 2, and therefore the refrigerant recovery time can be shortened, especially in environments where the outside air temperature is low.

[0095] In the first embodiment, in the cooling mode, the air conditioning expansion valve 21 is opened to an extent that the refrigerant evaporates, and the refrigerant output from the compressor 11 passes through the indoor heat exchanger 12, the air conditioning expansion valve 21, and the evaporator 17 in that order before flowing back into the compressor 11. In the heating mode, the air conditioning expansion valve 21 is closed and the two-way valve 13 is closed, and the refrigerant output from the compressor 11 passes through the indoor heat exchanger 12 and the orifice 14 in that order before flowing back into the compressor 11. In the refrigerant heating step of the refrigerant recovery mode, the air conditioning expansion valve 21 is closed and the two-way valve 13 is opened, and the refrigerant output from the compressor 11 passes through the indoor heat exchanger 12 and the two-way valve 13 in that order before flowing back into the compressor 11. The refrigerant recovery mode and the heating mode differ only in the state of the two-way valve 13. When it becomes necessary to extract the refrigerant in a low outside temperature environment where the heating mode is to be executed, it is sufficient to switch the two-way valve 13 and perform the same operation as in the heating mode, thereby making it easy to recover the refrigerant.

[0096] In the first embodiment, the refrigerant heating step includes a first circulation step in which the air-conditioning expansion valve 21 is fully closed and the two-way valve 13 is open, causing the refrigerant output from the compressor 11 to pass through the indoor heat exchanger 12 and the two-way valve 13 in that order, and then flow back into the compressor 11; and a second circulation step in which, after the first circulation step, the air-conditioning expansion valve 21 is fully opened and the two-way valve 13 is open, causing the refrigerant to pass through the indoor heat exchanger 12, the air-conditioning expansion valve 21, and the evaporator 17 in that order, and then flow back into the compressor 11. By supplying high-temperature, high-pressure refrigerant to the path (cooling piping 2a) that supplies refrigerant to the evaporator 17, the refrigerant remaining in the path can be efficiently recovered. This shortens the refrigerant recovery time.

[0097] Furthermore, in the first and second circulation steps, the battery-side expansion valve 22 is fully closed. The refrigerant heating step further includes a third circulation step after the first circulation step, in which the air-conditioning-side expansion valve 21 is fully closed, the battery-side expansion valve 22 is fully opened, and the two-way valve 13 is open, causing the refrigerant to pass through the indoor heat exchanger 12, the two-way valve 13, and the battery heat exchanger 18 in that order, and then flow back into the compressor 11. By supplying high-temperature, high-pressure refrigerant to the path (battery piping 2c) that supplies refrigerant to the battery heat exchanger 18, the refrigerant remaining in the path can be efficiently recovered. In particular, by fully closing the air-conditioning-side expansion valve 21, the refrigerant path can be shortened as much as possible, allowing the refrigerant to be efficiently recovered. This shortens the refrigerant recovery time.

[0098] Furthermore, in the first embodiment, the process proceeds to the second circulation step when at least one of the following conditions is met: the refrigerant temperature is equal to or higher than a first predetermined temperature in the first circulation step; and the refrigerant pressure is equal to or higher than a first predetermined pressure in the first circulation step. Since the process proceeds to the second circulation step when at least one of the temperature and pressure of the refrigerant in the refrigerant circuit 2 is sufficiently high, high-temperature, high-pressure refrigerant can be sent all at once to the path that supplies refrigerant to the evaporator 17. This allows the refrigerant remaining in the path to be efficiently recovered, shortening the refrigerant recovery time.

[0099] Furthermore, in the first embodiment, the process proceeds to the extraction step when at least one of the following conditions is met: the refrigerant temperature is a second predetermined temperature higher than the first predetermined temperature in the second or third circulation step; and the refrigerant pressure is a second predetermined pressure higher than the first predetermined pressure in the second or third circulation step. When the refrigerant temperature reaches the second predetermined temperature or the refrigerant pressure reaches the second predetermined pressure, it can be determined that all of the refrigerant in the refrigerant circuit 2 has vaporized. By proceeding to the extraction step in this state, the refrigerant can be efficiently extracted. This shortens the refrigerant recovery time.

[0100] In the first embodiment, the outlet 20 is provided in the refrigerant circuit 2 at a position downstream of the indoor heat exchanger 12 and the evaporator 17 and upstream of the compressor 11. By providing the outlet 20 at a position where the refrigerant pressure is low, the refrigerant can be efficiently collected, thereby shortening the refrigerant collection time.

[0101] Second Embodiment Hereinafter, the second embodiment will be described in detail with reference to the drawings. In the following description, parts common to the first embodiment will be given the same reference numerals and detailed description thereof will be omitted.

[0102] (8) Overall configuration of vehicle air conditioning system In the second embodiment, the configuration of a refrigerant circuit 202 of an air conditioner 201 is different from that of the first embodiment. Specifically, as shown in Fig. 9, a heater core 212 and a battery heat exchanger 18 are not provided on the refrigerant circuit 202. A water-cooled condenser 221 and a battery chiller 231 are arranged in the refrigerant circuit 202.

[0103] The heater core 212 is disposed on a first coolant circuit 220 that includes a water-cooled condenser 221. The first coolant circuit 220 has a first water pump 222. Although not shown, the first coolant circuit 220 passes through a water jacket of the motor, and the first coolant flowing through the first coolant circuit 220 exchanges heat with the motor. The first coolant is discharged from the first water pump 222, absorbs heat in the water-cooled condenser 221 and the water jacket, dissipates heat in the heater core 212, and flows back into the first water pump 222. The water-cooled condenser 221 constitutes a heat exchanger for heating.

[0104] The battery heat exchanger 18 is disposed on a second coolant circuit 230 that includes a battery chiller 231. The second coolant circuit 230 has a second water pump 232. The second coolant flowing through the second coolant circuit 230 is discharged from the second water pump 232, dissipates heat in the battery chiller 231, absorbs heat in the battery heat exchanger 18, and then flows back into the second water pump 232. The battery chiller 231 constitutes a battery temperature adjustment unit.

[0105] The refrigerant circuit 202 according to the second embodiment is provided with a heat exchange pipe 202a in which the outdoor heat exchanger 15 is provided, and a bypass pipe 202b that bypasses the outdoor heat exchanger 15. A first two-way valve 213 is disposed in the heat exchange pipe 202a upstream of the outdoor heat exchanger 15. A second two-way valve 214 is provided in the bypass pipe 202b. When the first two-way valve 213 is open and the second two-way valve 214 is closed, the refrigerant flows into the heat exchange pipe 202a. Conversely, when the first two-way valve 213 is closed and the second two-way valve 214 is open, the refrigerant flows into the bypass pipe 202b.

[0106] The air conditioning pipe 202c and the battery pipe 202d extend from the path where the heat exchange pipe 202a and the bypass pipe 202b join together. The evaporator 17 is disposed midway along the air conditioning pipe 202c. The battery pipe 202d constitutes a path branching off from the path from the water-cooled condenser 221 to the evaporator 17. A battery chiller 231 is disposed midway along the battery pipe 202d.

[0107] The refrigerant circuit 202 is provided with a plurality of sensors that detect the state of the refrigerant flowing through the circuit. The plurality of sensors includes a fifth temperature sensor ST5, a sixth temperature sensor ST6, a seventh temperature sensor ST7, an eighth temperature sensor ST8, a third pressure sensor SP3, and a fourth pressure sensor SP4.

[0108] The fifth temperature sensor ST5 is disposed in the refrigerant circuit 2 at a position downstream of the compressor 11 and upstream of the water-cooled condenser 221. The fifth temperature sensor ST5 detects the temperature of the refrigerant immediately after it is output from the compressor 11.

[0109] The sixth temperature sensor ST6 is disposed downstream of the junction of the heat exchange pipe 202a and the bypass pipe 202b and upstream of the air conditioning pipe 202c and the battery pipe 202d in the refrigerant circuit 2. The sixth temperature sensor ST6 detects the temperature of the refrigerant output from the compressor 11 and after heat exchange with at least the water-cooled condenser 221.

[0110] The seventh temperature sensor ST7 is disposed in a position on the cooling pipe 202c downstream of the evaporator 17 and upstream of the junction with the battery pipe 202d. The seventh temperature sensor ST7 detects the temperature of the refrigerant after heat exchange with the air for air conditioning by the evaporator 17.

[0111] The eighth temperature sensor ST8 is disposed in a position on the battery pipe 202d downstream of the battery chiller 231 and upstream of the junction with the air conditioning pipe 202c. The eighth temperature sensor ST8 detects the temperature of the refrigerant after heat exchange with the second coolant by the battery chiller 231.

[0112] The third pressure sensor SP3 is disposed downstream of the junction of the heat exchange pipe 202a and the bypass pipe 202b and upstream of the air conditioning pipe 202c and the battery pipe 202d in the refrigerant circuit 2. The third pressure sensor SP3 detects the pressure of the refrigerant output from the compressor 11 and after heat exchange with at least the water-cooled condenser 221.

[0113] The fourth pressure sensor SP4 is disposed in the battery pipe 202d downstream of the battery chiller 231 and upstream of the junction with the air conditioning pipe 202c. The fourth pressure sensor SP4 detects the pressure of the refrigerant after heat exchange with the second coolant by the battery chiller 231.

[0114] (9) Vehicle air conditioning control system The air conditioner 201 is controlled by a controller 100. The configuration of the controller 100 is the same as that of the first embodiment, and therefore a detailed description thereof will be omitted.

[0115] 10, the controller 100 receives an external command ES and signals from the temperature sensors ST5 to ST8 and the pressure sensors SP3 and SP4. The external command ES is a cooling request, a heating request, a request to change the air conditioning temperature, etc. The external command ES also includes a refrigerant recovery request to recover refrigerant from the refrigerant circuit 2.

[0116] The controller 100 determines the operating state of the air conditioner 201 based on the external command ES and signals from the temperature sensors ST5 to ST8 and the pressure sensors SP3 and SP4, and calculates the control amount of each device according to a predetermined control logic. The control logic is stored in memory. The control logic includes calculating the target amount and the control amount using maps and arithmetic expressions stored in the memory.

[0117] The controller 100 outputs electrical signals related to the calculated control variables to the compressor 11, the first two-way valve 213, the second two-way valve 214, the air conditioning side expansion valve 21, the battery side expansion valve 22, the radiator fan 15a, and the grill shutter 15b.

[0118] (10) Cooling mode When there is a cooling request, the controller 100 switches the refrigerant circuit 202 to the cooling mode and circulates the refrigerant. Figure 11 shows the refrigerant flow path in the cooling mode. Figure 11 also shows the refrigerant flow path when there is a battery cooling request in the cooling mode.

[0119] In the cooling mode, the first two-way valve 213 is open, and the second two-way valve 214 is closed. In the refrigerant mode, the air conditioning expansion valve 21 is adjusted to an opening degree that vaporizes the refrigerant by reducing the pressure. In the refrigerant mode, the battery-side expansion valve 22 is adjusted to an opening degree that vaporizes the refrigerant by reducing the pressure. In the cooling mode, the refrigerant is vaporized by the air conditioning expansion valve 21 and the battery-side expansion valve 22, so it can be said that the refrigerant adjustment unit is in a first state in which the refrigerant is vaporized by reducing the pressure.

[0120] The refrigerant is compressed by the compressor 11 and passes in the state of high-pressure gas through the water-cooled condenser 221. The refrigerant flows into the heat exchange pipe 202a, and is liquefied by dissipating heat to the air outside the vehicle by the exterior heat exchanger 15.

[0121] In the cooling pipe 202c, the refrigerant is vaporized by reducing the pressure by the air conditioning expansion valve 21. The vaporized refrigerant passes through the evaporator 17, where it absorbs heat from the air for air conditioning.

[0122] The refrigerant that has flowed into the battery pipe 202d is decompressed and vaporized by the battery-side expansion valve 22. The vaporized refrigerant passes through the battery chiller 231 and exchanges heat with the second cooling water in the battery chiller 231.

[0123] The refrigerant that has passed through the cooling pipe 202c and the battery pipe 202d passes through the accumulator 19, and then flows into the compressor 11 again as a low-pressure gas.

[0124] In the cooling mode, the refrigerant circulates through the refrigerant circuit 202 as described above. When the cooling mode is selected and there is no demand for battery cooling, the battery-side expansion valve 22 is fully closed. The refrigerant does not flow into the battery pipe 202d, but passes through the air conditioning-side expansion valve 21 and flows into the evaporator 17.

[0125] (11) Heating mode When a heating request is made, the controller 100 sets the refrigerant circuit 2 to the heating mode and circulates the refrigerant. Figure 12 shows the flow path of the refrigerant in the heating mode.

[0126] In the heating mode, the first two-way valve 213 is closed, and the second two-way valve 214 is open. In the heating mode, the air conditioning-side expansion valve 21 is fully closed. In the heating mode, the battery-side expansion valve 22 is adjusted to an opening degree that vaporizes the refrigerant by reducing the pressure. In the heating mode, the refrigerant is vaporized by the battery-side expansion valve 22, so the refrigerant adjustment unit can be said to be in a first state in which the refrigerant is vaporized by reducing the pressure.

[0127] The refrigerant is compressed by the compressor 11 and passes through the water-cooled condenser 221 in the state of a high-pressure gas. The refrigerant dissipates heat into the first cooling water in the water-cooled condenser 221 and is liquefied. The refrigerant passes through the bypass piping 202b and then flows into the battery piping 202d. The refrigerant that flows into the battery piping 202d is depressurized by the battery-side expansion valve 22 and vaporizes. The vaporized refrigerant passes through the battery chiller 231 and exchanges heat with the second cooling water in the battery chiller 231. The refrigerant that has passed through the battery piping 202d passes through the accumulator 19 and then flows into the compressor 11 again as a low-pressure gas.

[0128] (12) Refrigerant recovery mode In the second embodiment, the refrigerant recovery mode includes a first circulation step, a second circulation step, and a removal step. In the second embodiment, the refrigerant recovery mode is also executed when a request signal is input to the controller 100 by an operator removing the refrigerant while the vehicle is stopped.

[0129] (12-1) First circulation step The refrigerant circulation path in the first circulation step is the same as that in the heating mode, as shown in Figure 12. In the first circulation step, the first two-way valve 213 is closed, and the second two-way valve 214 is open. In the first circulation step, the air conditioning side expansion valve 21 is fully closed. In the first circulation step, the battery side expansion valve 22 is fully open. In the first circulation step, the refrigerant does not vaporize due to pressure reduction, so the refrigerant adjustment unit can be said to be in a second state in which refrigerant vaporization due to pressure reduction is not performed.

[0130] The refrigerant is compressed by the compressor 11, passes through the water-cooled condenser 221 in the state of high-pressure gas, and then flows into the bypass pipe 202b. The refrigerant passes through the bypass pipe 202b and flows into the battery pipe 202d, and then passes through the battery-side expansion valve 22 without being reduced in pressure. The refrigerant then passes through the battery chiller 231 and the accumulator 19, and then flows into the compressor 11 again.

[0131] In the second embodiment, too, in the first circulation step, the refrigerant is circulated through the shortest circulation path without being decompressed. As the refrigerant continues to be compressed by the compressor 11, it reaches a high temperature and vaporizes. In the first circulation step, by circulating the refrigerant through the shortest circulation path, the refrigerant can be efficiently brought to a high temperature and high pressure state. In the second embodiment, too, the refrigerant recovery mode is a mode that is executed while the vehicle is stopped, so even if the refrigerant passes through the water-cooled condenser 221 and the battery chiller 231, the refrigerant hardly releases heat.

[0132] (12-2) Second circulation step FIG. 13 shows the refrigerant flow path in the second circulation step. The second circulation step is a step for vaporizing the refrigerant remaining in the heat exchange pipe 202a and the cooling pipe 202c. The second circulation step is executed after the first circulation step. The timing of transition from the first circulation step to the second circulation step is determined by the detection value of the sixth temperature sensor ST6 and the detection value of the third pressure sensor SP3. Specifically, transition to the second circulation step occurs when the detection value of the sixth temperature sensor ST6 becomes equal to or greater than a first predetermined temperature Tc1 or when the detection value of the third pressure sensor SP3 becomes equal to or greater than a first predetermined pressure Pc1. Note that the timing of transition to the second circulation step may also be determined by the detection values ​​of the fifth temperature sensor ST5, the eighth temperature sensor ST8, and the fourth pressure sensor SP4.

[0133] In the second circulation step, the first two-way valve 213 is in an open state, and the second two-way valve 214 is in a closed state. In the second circulation step, the air conditioning-side expansion valve 21 is in a fully open state, and the battery-side expansion valve 22 is in a fully closed state. In the second circulation step, the refrigerant does not vaporize due to pressure reduction, so the refrigerant adjustment unit can be said to be in a second state in which refrigerant vaporization due to pressure reduction is not performed.

[0134] The refrigerant is compressed by the compressor 11, passes through the water-cooled condenser 221 in the state of high-pressure gas, and then flows into the heat exchange pipe 202a. The refrigerant passes through the outdoor heat exchanger 15 and flows into the cooling pipe 202c. In the cooling pipe 202c, the refrigerant passes through the air conditioning expansion valve 21 without being decompressed, and then passes through the evaporator 17. The refrigerant then passes through the accumulator 19 and flows into the compressor 11 again.

[0135] In the second circulation step, the refrigerant is circulated through the heat exchange pipe 202a and the cooling pipe 202c without being decompressed. As a result, even if refrigerant is present in the heat exchange pipe 202a and the cooling pipe 202c, the refrigerant in the heat exchange pipe 202a and the cooling pipe 202c can be brought to a high-temperature and high-pressure state. In particular, even if the refrigerant is present in a liquid state in the heat exchange pipe 202a and the cooling pipe 202c, the refrigerant can be completely vaporized.

[0136] (12-3) Removal step The removal step is performed after the second circulation step is completed. The timing of transition from the second circulation step to the removal step is determined by the detection value of the sixth temperature sensor ST6 and the detection value of the third pressure sensor SP3. Specifically, transition to the removal step occurs when the detection value of the sixth temperature sensor ST6 becomes equal to or higher than the second predetermined temperature Tc2 or the detection value of the third pressure sensor SP3 becomes equal to or higher than the second predetermined pressure Pc2. The second predetermined temperature Tc2 is a temperature higher than the first predetermined temperature Tc1. The second predetermined pressure Pc2 is a pressure higher than the first predetermined pressure Pc1. The timing of transition to the removal step may also be determined by the detection value of the fifth temperature sensor ST5 and the detection value of the seventh temperature sensor ST7.

[0137] In the extraction step, all valves are opened. Specifically, the first two-way valve 213 and the second two-way valve 214 are both open, and the air-conditioning expansion valve 21 and the battery expansion valve 22 are both fully open. In addition, the compressor 11 is stopped.

[0138] After all the valves are opened and the compressor 11 is stopped, the outlet 20 is opened. The outlet 20 is manually opened by an operator. Because the refrigerant in the refrigerant circuit 202 is in a high-temperature and high-pressure state, the refrigerant is efficiently discharged from the outlet 20 even when the compressor 11 is stopped. Note that, in order to reliably discharge the refrigerant from the refrigerant circuit 202, a vacuum pump may be connected to the outlet 20 to suck out the refrigerant.

[0139] (13) Flowchart Next, the processing of the controller 100 in the refrigerant recovery mode will be described with reference to Fig. 14. In the following description, the compressor 11 is operating unless otherwise specified.

[0140] First, in step S201, the controller 100 determines whether or not a refrigerant recovery mode command has been issued. If the result is YES, that is, the controller 100 proceeds to step S202. On the other hand, if the result is NO, that is, the controller 100 has not issued a refrigerant recovery mode command, the controller 100 ends the process.

[0141] In step S202, the controller 100 performs a first circulation step in which the controller 100 closes the first two-way valve 213, opens the second two-way valve 214, fully closes the air conditioning expansion valve 21, and fully opens the battery expansion valve 22.

[0142] Next, in step S203, the controller 100 determines whether the detection value T of the sixth temperature sensor ST6 is equal to or greater than the first predetermined temperature Tc1. If the result is YES, that is, the detection value T of the sixth temperature sensor ST6 is equal to or greater than the first predetermined temperature Tc1, the controller 100 proceeds to step S205. On the other hand, if the result is NO, that is, the detection value T of the sixth temperature sensor ST6 is less than the first predetermined temperature Tc1, the controller 100 proceeds to step S204.

[0143] In step S204, the controller 100 determines whether the detection value P of the third pressure sensor SP3 is equal to or greater than the first predetermined pressure Pc1. If the detection value P of the third pressure sensor SP3 is equal to or greater than the first predetermined pressure Pc1 (YES), the controller 100 proceeds to step S205. On the other hand, if the detection value P of the third pressure sensor SP3 is less than the first predetermined pressure Pc1 (NO), the controller 100 returns to step S203.

[0144] In step S205, the controller 100 performs a second circulation step in which the controller 100 opens the first two-way valve 213, closes the second two-way valve 214, fully opens the air-conditioning expansion valve 21, and fully closes the battery-side expansion valve 22.

[0145] Next, in step S206, the controller 100 determines whether the detection value T of the sixth temperature sensor ST6 is equal to or greater than the second predetermined temperature Tc2. If the result is YES, that is, the detection value T of the sixth temperature sensor ST6 is equal to or greater than the second predetermined temperature Tc3, the controller 100 proceeds to step S108. On the other hand, if the result is NO, that is, the detection value T of the sixth temperature sensor ST6 is less than the second predetermined temperature Tc2, the controller 100 proceeds to step S207.

[0146] In step S207, the controller 100 determines whether the detection value P of the third pressure sensor SP3 is equal to or greater than the second predetermined pressure Pc2. If the result is YES, that is, the detection value P of the third pressure sensor SP3 is equal to or greater than the second predetermined pressure Pc2, the controller 100 proceeds to step S208. On the other hand, if the result is NO, that is, the detection value P of the third pressure sensor SP3 is less than the second predetermined pressure Pc2, the controller 100 returns to step S206.

[0147] In step S208, the controller 100 performs a removal step. The controller 100 opens the first two-way valve 213, opens the second two-way valve 214, fully opens the air-conditioning-side expansion valve 21, and fully opens the battery-side expansion valve 22. The controller 100 also stops the compressor 11. After step S208, the controller 100 ends the processing.

[0148] After the compressor 11 is stopped in step S208, the outlet 20 is opened by an operator, and the refrigerant is taken out of the refrigerant circuit 2.

[0149] (14) Effects of the Second Embodiment In the second embodiment, too, in the refrigerant recovery mode in which the refrigerant is extracted from the refrigerant circuit 2, a refrigerant heating step (steps S202 and S205) is performed in which the refrigerant output from the compressor 11 is circulated within the refrigerant circuit 2 without vaporizing the refrigerant by reducing the pressure within the refrigerant circuit 2, and a extraction step (step S208) is performed in which the extraction port 20 is opened after the refrigerant heating step. This increases the temperature and pressure of the refrigerant within the refrigerant circuit 2, allowing the refrigerant to be efficiently recovered. This shortens the refrigerant recovery time.

[0150] In the second embodiment, in the cooling mode and the heating mode, the battery-side expansion valve 22 is opened to an opening degree that evaporates the refrigerant, whereas in the first circulation step of the refrigerant recovery mode, the battery-side expansion valve 22 is opened to an opening degree that does not evaporate the refrigerant, and in the second circulation step of the refrigerant recovery mode, the battery-side expansion valve 22 is fully closed. In the first circulation step, the refrigerant remaining in the path (battery piping 202d) that supplies the refrigerant to the battery chiller 231 can be heated to a high temperature and high pressure. This shortens the time required to recover the refrigerant.

[0151] In particular, in the second embodiment, the only difference between the heating mode and the first circulation step of the refrigerant recovery mode is the opening degree of the battery-side expansion valve 22. Therefore, when it becomes necessary to extract refrigerant in a low-temperature environment where the heating mode is performed, it is sufficient to perform the same operation as in the heating mode with the opening degree of the battery-side expansion valve 22 changed. Therefore, the refrigerant can be easily recovered.

[0152] (15) Other embodiments The technology disclosed herein is not limited to the above-described embodiments, and can be substituted within the scope of the claims.

[0153] For example, in the above-described first and second embodiments, the refrigerant removal step is performed after the refrigerant heating step is completed, i.e., after stopping the compressor 11. However, the present invention is not limited to this, and the refrigerant removal step may be performed while the refrigerant heating step is being performed, i.e., while the compressor 11 is still operating.

[0154] In the first and second embodiments, the process proceeds to the discharge step when at least one of the following conditions is met: the refrigerant temperature is a second predetermined temperature higher than the first predetermined temperature, and the refrigerant pressure is a second predetermined pressure higher than the first predetermined pressure. However, the process may proceed to the discharge step when at least one of the following conditions is met: the refrigerant temperature is the first predetermined temperature, and the refrigerant pressure is the first predetermined pressure in the second circulation step or the third circulation step. Alternatively, only one of the refrigerant temperature and the refrigerant pressure may be used as the determination criterion.

[0155] In the first embodiment, the determination of whether to transition from the third circulation step to the next step was based on the refrigerant temperature detected by the first temperature sensor ST1 and the refrigerant pressure detected by the first pressure sensor SP1, but may also be based on the refrigerant temperature detected by the fourth temperature sensor ST4 and the refrigerant pressure detected by the second pressure sensor SP2. In the second embodiment, the determination of whether to transition from the first circulation step to the next step was based on the refrigerant temperature detected by the sixth temperature sensor ST6 and the refrigerant pressure detected by the third pressure sensor SP3, but may also be based on the refrigerant temperature detected by the eighth temperature sensor ST8 and the refrigerant pressure detected by the fourth pressure sensor SP4.

[0156] In addition, in the first and second embodiments, the air-conditioning-side expansion valve 21 constitutes a refrigerant adjustment unit and a first switching unit, and the battery-side expansion valve 22 constitutes a refrigerant adjustment unit and a second switching unit. However, this is not limiting, and a device that can switch between an open state in which the refrigerant passes through the evaporator 17 and a closed state in which the refrigerant does not pass through the evaporator 17 may be provided as a first switching unit separately from the air-conditioning-side expansion valve 21. Similarly, a device that can switch between an open state in which the refrigerant passes through the battery heat exchanger 18 and a closed state in which the refrigerant does not pass through the battery heat exchanger 18 may be provided as a second switching unit separately from the battery-side expansion valve 22.

[0157] The above-described embodiments are merely examples and should not be construed as limiting the scope of the present disclosure. The scope of the present disclosure is defined by the claims, and all modifications and variations that fall within the scope of the claims equivalents are within the scope of the present disclosure. [Industrial Applicability]

[0158] The techniques disclosed herein are useful for removing refrigerant from a vehicle air conditioner. [Explanation of symbols]

[0159] 1. Vehicle air conditioning system 2 Refrigerant circuit 3 Battery 11 Compressor 12 Indoor heat exchanger (air conditioning unit, heating heat exchanger) 13 Two-way valve (refrigerant adjustment section) 14 Orifice (refrigerant adjustment part) 17 Evaporator (air conditioning section) 18 Battery heat exchanger (battery temperature adjustment unit) 21 Air conditioning side expansion valve (first switching unit, refrigerant adjustment unit) 22 Battery side expansion valve (second switching unit, refrigerant adjustment unit) 20 Outlet 100 Controllers 201 Vehicle air conditioning system 202 Refrigerant circuit 212 Heater core (air conditioning unit, heating heat exchanger) 221 Water-cooled condenser 231 Battery Chiller SP1 First pressure sensor SP2 Second pressure sensor SP3 3rd pressure sensor SP4 4th pressure sensor ST1 First temperature sensor ST2 Second temperature sensor ST3 Third temperature sensor ST4 4th temperature sensor ST5 5th temperature sensor ST6 6th temperature sensor ST7 7th temperature sensor ST8 8th temperature sensor

Claims

1. A method for extracting refrigerant from an air conditioning system for a vehicle that conditions the air inside a vehicle cabin using refrigerant circulating in a refrigerant circuit, comprising: The vehicle air conditioning device includes: an air conditioning unit for conditioning the air in the vehicle interior; a refrigerant adjusting unit that can change between a first state in which the refrigerant is vaporized by decompression and a second state in which the refrigerant is not vaporized by decompression; a compressor that compresses the refrigerant and then outputs it; an outlet for taking the refrigerant out of the refrigerant circuit; Including, In a cooling mode and a heating mode in which the refrigerant is used to condition the air inside the vehicle cabin, the refrigerant adjustment unit is set to the first state, and the refrigerant output from the compressor passes through the air conditioning unit and the refrigerant adjustment unit, and then flows back into the compressor to circulate within the refrigerant circuit; In a refrigerant recovery mode in which the refrigerant is extracted from the refrigerant circuit, a refrigerant heating step of setting the refrigerant adjustment unit to the second state, causing the refrigerant output from the compressor to pass through the air conditioning unit and the refrigerant adjustment unit in this order, and then causing the refrigerant to flow back into the compressor and circulate within the refrigerant circuit; a removal step of opening the outlet after the refrigerant heating step or during the refrigerant heating step; A method for removing refrigerant from an air conditioning system for a vehicle, comprising:

2. 2. The method for removing refrigerant from a vehicle air conditioner according to claim 1, the air conditioning unit has a heating heat exchanger and an evaporator, The vehicle air conditioning device further includes a first switching unit that is switchable between an open state in which the refrigerant passes through the evaporator and a closed state in which the refrigerant does not pass through the evaporator, In the cooling mode, the first switching unit is set to the open state and the refrigerant adjustment unit is set to the first state, and the refrigerant output from the compressor passes through the heating heat exchanger, the refrigerant adjustment unit, and the evaporator in this order, and then flows into the compressor again; In the heating mode, the first switching unit is set to the closed state and the refrigerant adjustment unit is set to the first state, and the refrigerant output from the compressor passes through the heating heat exchanger and the refrigerant adjustment unit in this order, and then flows into the compressor again; In the refrigerant heating step of the refrigerant recovery mode, the first switching unit is set to the closed state and the refrigerant adjustment unit is set to the second state, and the refrigerant output from the compressor passes through the heating heat exchanger and the refrigerant adjustment unit in that order, and then flows into the compressor again.

3. 3. The method for removing refrigerant from a vehicle air conditioner according to claim 2, The refrigerant heating step includes: a first circulation step of setting the first switching unit to the closed state and the refrigerant adjustment unit to the second state, causing the refrigerant output from the compressor to pass through the heating heat exchanger and the refrigerant adjustment unit in this order, and then causing the refrigerant to flow into the compressor again; a second circulation step in which, after the first circulation step, the first switching unit is set to the open state and the refrigerant adjustment unit is set to the second state, the refrigerant passes through the heating heat exchanger, the refrigerant adjustment unit, and the evaporator in this order, and then flows into the compressor again; A method for removing refrigerant from an air conditioning system for a vehicle, comprising:

4. 4. The method for removing refrigerant from a vehicle air conditioner according to claim 3, The vehicle air conditioning device includes: a battery temperature adjusting unit that adjusts the temperature of a battery that is located on a path branching from a path from the heating heat exchanger to the evaporator in the refrigerant circuit and that supplies electric power to an electric motor that generates driving force for the vehicle; a second switching unit that is switchable between an open state in which the refrigerant passes through the battery temperature adjustment unit and a closed state in which the refrigerant does not pass through the battery temperature adjustment unit; Further comprising: In the first circulation step and the second circulation step, the second switching unit is set to the closed state, the refrigerant heating step further includes, after the first circulation step, a third circulation step of setting the first switching unit to the closed state, the second switching unit to the open state, and the refrigerant adjustment unit to the second state, causing the refrigerant to pass through the heating heat exchanger, the refrigerant adjustment unit, and the battery temperature adjustment unit in that order, and then flowing into the compressor again.

5. 4. The method for removing refrigerant from a vehicle air conditioner according to claim 3, the vehicle air conditioning system further includes a battery temperature adjustment unit that adjusts the temperature of a battery that is located in a path branching from a path from the heating heat exchanger to the evaporator in the refrigerant circuit and that supplies electric power to an electric motor that generates driving force for the vehicle, the refrigerant adjustment unit has an expansion valve that is provided in the battery temperature adjustment unit and has an adjustable opening degree; A method for removing refrigerant from an air conditioning system for a vehicle, wherein in the cooling mode and the heating mode, the expansion valve is opened to an opening degree that causes the refrigerant to evaporate, while in the first circulation step of the refrigerant recovery mode, the expansion valve is opened to an opening degree that causes the refrigerant not to evaporate, and in the second circulation step of the refrigerant recovery mode, the expansion valve is fully closed.

6. The refrigerant removal method for a vehicle air conditioner according to any one of claims 3 to 5, The vehicle air conditioning device includes: a temperature sensor for detecting a refrigerant temperature in the refrigerant circuit; a pressure sensor for detecting a refrigerant pressure in the refrigerant circuit; Further comprising: A refrigerant extraction method for a vehicle air conditioning system, which proceeds to the second circulation step when at least one of the following conditions is met: the refrigerant temperature detected by the temperature sensor in the first circulation step is equal to or higher than a first predetermined temperature; and the refrigerant pressure detected by the pressure sensor in the first circulation step is equal to or higher than a first predetermined pressure.

7. 7. The method for removing refrigerant from a vehicle air conditioner according to claim 6, a refrigerant extraction method for a vehicle air conditioning system, the method proceeding from the refrigerant heating step to the extraction step when at least one of the following conditions is met: the refrigerant temperature detected by the temperature sensor is a second predetermined temperature higher than the first predetermined temperature; and the refrigerant pressure detected by the pressure sensor is a second predetermined pressure higher than the first predetermined pressure.

8. An air conditioning system for a vehicle that conditions the air inside a vehicle cabin using a refrigerant circulating through a refrigerant circuit, an air conditioning unit for conditioning the air in the vehicle interior; a refrigerant adjusting unit that can change between a first state in which the refrigerant is vaporized by decompression and a second state in which the refrigerant is not vaporized by decompression; a compressor that compresses the refrigerant and then outputs it; an outlet for taking the refrigerant out of the refrigerant circuit; a controller; The controller In a cooling mode and a heating mode in which the refrigerant is used to condition the air inside the vehicle cabin, the refrigerant adjustment unit is set to the first state, and the refrigerant output from the compressor passes through the air conditioning unit and the refrigerant adjustment unit, and then flows back into the compressor to circulate within the refrigerant circuit; In a refrigerant recovery mode in which the refrigerant is extracted from the refrigerant circuit, the refrigerant adjustment unit is set to the second state before the extraction port is opened, and the refrigerant output from the compressor passes through the air conditioning unit and the refrigerant adjustment unit, and then flows back into the compressor, circulating the refrigerant within the refrigerant circuit.

9. 9. The vehicle air conditioning system according to claim 8, The outlet is provided downstream of the air conditioning unit in the refrigerant circuit.

Images