Vehicle air conditioning device

Abstract

The present invention provides a vehicle air-conditioning device that does not perform a refrigerant recovery operation of a refrigerant circuit when an operation mode of the refrigerant circuit is switched or the like, can suppress a state in which a liquid refrigerant is retained in a refrigerant heat medium heat exchanger with a lower electric power, and can prevent a situation in which the refrigerant circuit is operated with too little refrigerant. A vehicle air-conditioning device for conditioning air in a vehicle cabin using heat dissipation and heat absorption of a refrigerant circuit is provided with: a refrigerant / heat medium heat exchanger for exchanging heat between a refrigerant and a heat medium in the refrigerant circuit; a heat medium circuit that circulates a heat medium; and a control device that controls the operation of the refrigerant circuit and the heat medium circuit. The control device executes a liquid refrigerant evaporation mode in which the liquid refrigerant is evaporated when it is estimated that the liquid refrigerant remains in the refrigerant-heat-medium heat exchanger.

Description

Technical Field

[0001] The present invention relates to an air conditioning device for vehicles. Background Art

[0002] As an air conditioning device for vehicles, a device using a heat pump type refrigerant circuit is known. In such an air conditioning device for vehicles, the refrigerant circuit generally includes a compressor, a heat exchanger for heat dissipation (condenser), an expansion mechanism, and a heat exchanger for heat absorption (evaporator), and the air in the vehicle compartment is conditioned by selectively dissipating heat from the heat exchanger for heat dissipation and absorbing heat from the heat exchanger for heat absorption inside and outside the vehicle compartment. In addition, the air conditioning device for vehicles includes a refrigerant heat medium heat exchanger (cooling heat exchanger) that exchanges heat between the low-temperature refrigerant flowing through the refrigerant circuit and the heat medium, and includes a heat medium circuit that cools a heating element such as a battery using the heat medium cooled here (see Patent Document 1 below). Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-3969 Summary of the Invention Technical Problem to be Solved by the Invention

[0004] The refrigerant heat medium heat exchanger of the above-described air conditioning device for vehicles contains low-temperature liquid refrigerant decompressed by the expansion mechanism, but the refrigerant does not always flow in the refrigerant heat medium heat exchanger. The flow path of the refrigerant circuit appropriately switches between the case where the refrigerant flows in the refrigerant heat medium heat exchanger and the case where the refrigerant flows in the bypass flow path of the refrigerant heat medium heat exchanger according to the operation mode of the air conditioning device for vehicles.

[0005] At this time, when the operation mode (cooling operation mode) in which the refrigerant flows is performed in the refrigerant heat medium heat exchanger (cooling heat exchanger), if the flow path to the refrigerant heat medium heat exchanger is stopped, it becomes a state where the liquid refrigerant remains in the refrigerant heat medium heat exchanger. When the refrigerant circuit is operated in the operation mode without using the refrigerant heat medium heat exchanger, it becomes a state of undercharging operation (an operation state where the amount of the circulating refrigerant becomes less), and there is a problem of deviating from the appropriate operation state. In addition, such a problem may also occur when the refrigerant circuit stops after the cooling operation mode is performed and then the refrigerant circuit is restarted.

[0006] Regarding the retention of the liquid refrigerant in the refrigerant heat medium heat exchanger of such a refrigerant circuit, an operation of operating the compressor in the initial operation of the next operation to recover the liquid refrigerant into the accumulator is also performed. However, this results in an increase in the power consumption of the battery due to the application of an excessive recovery operation, and therefore a method for suppressing the retention of the liquid refrigerant with lower power is required.

[0007] The present invention takes addressing such a situation as a technical problem. That is, the technical problem of the present invention is that when the operation mode of the refrigerant circuit is switched or restarted, the refrigerant recovery operation of the refrigerant circuit is not performed, but the state where liquid refrigerant stays in the refrigerant heat medium heat exchanger is suppressed with lower power, preventing the refrigerant circuit from operating with too little refrigerant in advance. Technical solution for solving the technical problem

[0008] To solve such a problem, the vehicle air conditioning device of the present invention includes the following structure. A vehicle air conditioning device that uses the heat dissipation and heat absorption of a refrigerant circuit to condition the air in the vehicle compartment, includes: a refrigerant heat medium heat exchanger that exchanges heat between the refrigerant of the refrigerant circuit and a heat medium; a heat medium circuit that circulates the heat medium; and a control device that controls the operations of the refrigerant circuit and the heat medium circuit. When it is presumed that liquid refrigerant stays in the refrigerant heat medium heat exchanger, the control device executes a liquid refrigerant evaporation mode for evaporating the liquid refrigerant. Advantages of the invention

[0009] According to the present invention having such features, in a vehicle air conditioning device, when the operation mode of the refrigerant circuit is switched, etc., the refrigerant recovery operation of the refrigerant circuit is not performed, and the state where liquid refrigerant stays in the refrigerant heat medium heat exchanger can be suppressed with lower power, preventing the refrigerant circuit from operating with too little refrigerant in advance. Description of the drawings

[0010] Figure 1 It is a diagram showing a schematic structure of a vehicle air conditioning device according to an embodiment of the present invention. Figure 2 It is a block diagram showing a schematic structure of an air conditioning controller as a control device of a vehicle air conditioning device according to an embodiment of the present invention. Figure 3 It is a flowchart for explaining the execution control operation of the liquid refrigerant evaporation mode (evaporation operation). Figure 4 It is a flowchart for explaining the stop control operation of the liquid refrigerant evaporation mode (evaporation operation). Detailed implementation mode

[0011] Hereinafter, for the mode for implementing the present invention (this embodiment), a detailed description will be given with reference to the drawings. In the following description, the same reference numerals denote parts having the same functions, and repeated descriptions in the drawings are appropriately omitted.

[0012] Figure 1 The vehicle air conditioner 1 shown performs air conditioning in the passenger compartment by using the heat dissipation and heat absorption of the refrigerant circuit R. This vehicle air conditioner 1 can be applied, for example, to vehicles such as electric vehicles (EVs) not equipped with an engine (internal combustion engine), and so-called hybrid vehicles that share an engine and a driving electric motor. Such vehicles are equipped with a battery 5 (for example, a lithium battery), and are driven and travel by supplying the electric power charged from an external power source to the battery 5 to a motor unit 6 including a driving electric motor (electric motor). The vehicle air conditioner 1 is also driven by using the electric power charged to the battery 5.

[0013] The vehicle air conditioner 1 has a refrigerant circuit R for performing heat pump operation and a heat medium circuit 4 for circulating a heat medium. The heat medium circuit 4 functions as an equipment temperature adjustment circuit for adjusting the temperatures of temperature adjustment objects such as the battery 5 and the motor unit 6, and functions as a waste heat recovery circuit for recovering waste heat from the above temperature adjustment objects. The refrigerant circuit R and the heat medium circuit 4 are Figure 2 controlled by an air conditioner controller 8 (control device) shown below. The heat medium circuit 4 is arranged in parallel with the refrigerant circuit R via a refrigerant heat medium heat exchanger (hereinafter referred to as a cooling heat exchanger) 14. In the cooling heat exchanger 14, the refrigerant flows through a refrigerant side flow path 14A, and the heat medium flows through a heat medium side flow path 14B.

[0014] The refrigerant circuit R forms a plurality of circulation paths through refrigerant pipes R1 to R12. In the refrigerant circuit R, during the circulation of the refrigerant compressed and discharged by a compressor (electric compressor) 2 in various paths, state changes of condensation (heat dissipation), decompression (expansion), and vaporization (heat absorption) occur, and the refrigerant obtained by gas-liquid separation by a liquid receiver 10 is sucked into the compressor 2.

[0015] The refrigerant circuit R includes a plurality of heat exchangers through which the refrigerant flows. Two of them are a first heat exchanger 11 and a second heat exchanger 12 arranged in an HVAC (Heating, Ventilating, and Air Conditioning) unit 3 having an air flow path 30 through which the air in the passenger compartment flows. The other two are an outdoor heat exchanger 13 arranged outside the passenger compartment and the above cooling heat exchanger 14.

[0016] The refrigerant circuit R is in Figure 1In the illustrated example, a flow path switching valve (solenoid valve) 20 is provided in the refrigerant pipe R3, a flow path switching valve (solenoid valve) 21 is provided in the refrigerant pipe R6, a check valve 22 is provided in the refrigerant pipe R9, and a check valve 23 is provided in the refrigerant pipe R5. In addition, in the illustrated refrigerant circuit R, a pressure reducing device 24 is provided in the refrigerant pipe R4, a pressure reducing device 25 is provided in the refrigerant pipe R7, and a pressure reducing device 26 is provided in the refrigerant pipe R11. Then, according to the switching of the operation mode of the air conditioner controller 8 (control device), the opening and closing of the flow path switching valves 20 and 21 and the pressure adjustment (including fully open and fully closed) of the pressure reducing devices (expansion valves) 24 to 26 are performed.

[0017] Here, the refrigerant pipes R11 and R12 of the refrigerant circuit R are branch flow paths for allowing the refrigerant to flow through the cooling heat exchanger 14. By opening the pressure reducing device (so-called cooling valve) 26 provided on the refrigerant pipe R11, the refrigerant including the decompressed liquid refrigerant flows into the cooling heat exchanger 14. By closing the pressure reducing device 26, the flow of the refrigerant to the cooling heat exchanger 14 is cut off. At this time, if the pressure reducing device 26 is closed in a state where there is liquid refrigerant in the cooling heat exchanger 14, a state where the liquid refrigerant remains in the cooling heat exchanger 14 may sometimes occur.

[0018] In the vehicle air conditioner 1, as operation modes of the heating operation that can be executed by the control of the air conditioner controller 8 (control device), for example, there are an external gas heat absorption heating mode in which the outdoor heat exchanger 13 absorbs external gas without using the cooling heat exchanger 14, a waste heat recovery heating mode in which the cooling heat exchanger 14 absorbs the waste heat recovered by the heat medium circuit 4, and a parallel heating mode in which the external gas heat absorption based on the outdoor heat exchanger 13 and the waste heat recovery heat absorption based on the cooling heat exchanger 14 are performed simultaneously.

[0019] In the external gas heat absorption heating mode, by closing the flow path switching valve 20, opening the flow path switching valve 21, and fully closing the pressure reducing device 25 and the pressure reducing device 26, the refrigerant circulating in the refrigerant circuit R is discharged from the compressor 2, passes through the refrigerant pipe R1, via the first heat exchanger 11, enters the refrigerant pipe R4 from the refrigerant pipe R2, passes through the pressure reducing device 24 and the outdoor heat exchanger 13, enters the refrigerant pipe R6, and reaches the accumulator 10 through the flow path switching valve 21 and the check valve 22. Therefore, in this operation mode, the inflow of the refrigerant to the cooling heat exchanger 14 is cut off.

[0020] In this external air heat absorption heating mode, the high-temperature and high-pressure refrigerant compressed by the compressor 2 is sent to the first heat exchanger 11 in the HVAC unit 3 that functions as a radiator, and the air sucked into the HVAC unit 3 from the internal air intake port 33 driven by the indoor blower 32 passes through the first heat exchanger 11 and is heated, and is blown out into the vehicle compartment from the blow-out port 31. At this time, the external air intake port 34 of the HVAC unit 3 is closed by the suction switching damper 35, and the air mixing damper 36 in the air flow path 30 opens only the flow path of the air toward the first heat exchanger 11.

[0021] In the waste heat recovery heating mode, by opening the flow path switching valve 20, closing the flow path switching valve 21, fully closing the pressure reducing device 25, and fully opening the pressure reducing device 26, the refrigerant circulating in the refrigerant circuit R is discharged from the compressor 2, passes through the refrigerant pipe R1, passes through the first heat exchanger 11, enters the refrigerant pipe R3 provided with the flow path switching valve 20 in the open state from the refrigerant pipe R2, passes through the refrigerant pipe R11 provided with the pressure reducing device 26, passes through the cooling heat exchanger 14, enters the refrigerant pipe R12, and reaches the accumulator 10. In this operation mode, the refrigerant including the liquid refrigerant flows into the cooling heat exchanger 14, where it absorbs heat from the heat medium circulating in the heat medium circuit 4.

[0022] In this waste heat recovery heating mode, as in the external gas absorption heating mode, the high-temperature and high-pressure refrigerant compressed by the compressor 2 is sent to the first heat exchanger 11 in the HVAC unit 3 which functions as a radiator. Driven by the indoor fan 32, the air sucked into the HVAC unit 3 from the internal gas intake port 33 passes through the first heat exchanger 11 to be heated, and is blown out from the blow-out port 31 into the vehicle compartment.

[0023] As in the above-mentioned waste heat recovery heating mode, the operation mode in which the refrigerant flows through the cooling heat exchanger 14 is hereinafter referred to as the cooling operation mode. The cooling operation mode is not limited to the above-mentioned waste heat recovery heating mode or parallel heating mode, and there are cooling temperature control modes for controlling the temperature of the temperature control object set on the heat medium circuit 4 during cooling operation, cooling defrosting modes for using waste heat recovered by the heat medium circuit 4 in the operation mode for defrosting the outdoor heat exchanger 13, and the like.

[0024] Figure 1 The heat medium circuit 4 shown in the figure includes an external gas heat medium heat exchanger 40, a heat medium storage tank 4T and a heat medium heater 7. The heat medium passing through the heat medium side flow path 14B of the cooling heat exchanger 14 is circulated by driving the circulation pumps 41 and 42 controlled by the air conditioning controller 8. Figure 1The shown heat medium circuit 4 can form multiple circulation flow paths by setting a three-way valve 43 and a check valve 44 and independently driving a circulation pump 41 and a circulation pump 42. Taking the circulation flow path as an example, the following situations can be switched, that is: the situation where the heat recovered from the battery 5 and the heat recovered from the motor unit 6 are respectively dissipated in the external gas heat medium heat exchanger 40 alone, the situation where these heats are combined and dissipated by the external gas heat medium heat exchanger 40, the situation where the heat recovered from the battery 5 and the heat recovered from the motor unit 6 respectively absorb heat from the cooling heat exchanger 14 alone, and the situation where these heats are combined and absorb heat from the cooling heat exchanger 14.

[0025] In addition, in Figure 1 ,"TS" represents a temperature sensor that measures the refrigerant temperature of the refrigerant circuit R, the heat medium temperature of the heat medium circuit 4, and the air temperature of the air flow path 30. "PTS" represents a refrigerant temperature sensor that measures the refrigerant temperature of the refrigerant circuit R and a refrigerant pressure sensor that measures the refrigerant pressure for inferring the refrigerant temperature of the refrigerant circuit R. In addition, "S" in the flow path switching valves 20, 21, and the three-way valve 43 represents an electric actuator for switching opening and closing, and "E" in the pressure reducing devices 24 - 26 represents an electric actuator for adjusting the opening and closing state (pressure adjustment state).

[0026] Figure 2 It shows a schematic structure of an air conditioning controller 8 which is a control device in charge of the control of the vehicle air conditioning device 1, especially the operation control of the refrigerant circuit R and the heat medium circuit 4. The air conditioning controller 8 is connected to a vehicle controller 9 (ECU) in charge of the control of the entire vehicle including the drive control of the motor unit 6 and the charge and discharge control of the battery 5 via a vehicle communication bus, and information is transmitted and received. Both the air conditioning controller 8 and the vehicle controller 9 (ECU) can be implemented as a microcomputer which is an example of a computer equipped with a processor.

[0027] The measurement information of various sensors 100 is input to the air conditioning controller 8 (control device). Based on the input measurement information, the compressor 2 of the refrigerant circuit R, the flow path switching valves 20, 21, the pressure reducing devices 24 - 26, the indoor blower 32, the intake switching damper 35, the air mixing damper 36 of the HVAC unit 3, the circulation pumps 41, 42 of the heat medium circuit 4, the heat medium heater 7, the three-way valve 43, etc. are controlled. The various sensors 100 include an external gas temperature sensor 101, a heat medium temperature sensor 102, a refrigerant temperature sensor 103, a refrigerant pressure sensor 104, an internal gas temperature sensor 105, etc. required for implementing the liquid refrigerant evaporation mode described later.

[0028] After the vehicle air conditioner 1 executes the above cooling operation mode, it sometimes executes an operation mode in which the refrigerant does not flow into the cooling heat exchanger 14, such as the external gas heat absorption heating mode. In addition, the vehicle air conditioner 1 sometimes stops the refrigerant circuit R after executing the above cooling operation mode. In such a case, since there is a situation where liquid refrigerant remains in the cooling heat exchanger 14, in order to eliminate this situation, a liquid refrigerant evaporation mode is executed in which the refrigerant circuit R is not driven and only the heat medium circuit 4 is driven to evaporate the remaining liquid refrigerant.

[0029] Hereinafter, Figure 3 the execution control operation of the liquid refrigerant evaporation mode (evaporation operation) of the air conditioner controller 8 will be described.

[0030] In step S1, the air conditioner controller 8 determines whether the external gas temperature of the vehicle detected by the external gas temperature sensor 101 is below a set threshold value (for example, 10 °C). When the air conditioner controller 8 determines that the external gas temperature is below the set threshold value (Yes in step S1), it proceeds to step S2. When it determines that the external gas temperature is not below the set threshold value (that is, higher than the set threshold value) (No in step S1), it is determined that no liquid refrigerant remains in the cooling heat exchanger 14, and Figure 3 a series of operation processes are ended.

[0031] In step S2, the air conditioner controller 8 determines whether it is possible to confirm that the current time is after the execution of the operation mode (cooling operation mode) in which the refrigerant flows through the coolant heat exchanger 14. In this step S2, when the air conditioner controller 8 can confirm that the current time is after the execution of the cooling operation mode (Yes in step S2), it proceeds to step S4. When it cannot confirm that the current time is after the execution of the cooling operation mode (No in step S2), it proceeds to step S3. When it is Yes in this step S2, since the cooling operation mode such as the waste heat recovery heating mode is executed in an environment with a relatively low external gas temperature, the air conditioner controller 8 presumes that liquid refrigerant remains in the cooling heat exchanger 14.

[0032] In step S3, the air conditioner controller 8 determines whether the outside air temperature of the vehicle detected by the outside air temperature sensor 101 is equal to or lower than the temperature of the air inside the passenger compartment (the in-vehicle temperature) detected by the in-vehicle temperature sensor 105. In this step S3, if the air conditioner controller 8 determines that the outside air temperature is lower than the in-vehicle temperature (Yes in step S3), it is also very likely to execute the cooling operation mode in the waste heat recovery heating mode or the like. Therefore, similar to the case where the answer in step S2 is Yes, it is presumed that the liquid refrigerant remains in the cooling heat exchanger 14, and the process proceeds to step S4. In step S3, if the air conditioner controller 8 determines that the outside air temperature is not lower than the in-vehicle temperature (i.e., higher than the in-vehicle temperature) (No in step S3), it is determined that the liquid refrigerant does not remain in the cooling heat exchanger 14, and the Figure 3 series of operation processes end.

[0033] In steps S4 to S7, when executing the liquid refrigerant evaporation mode (step S9) by circulating the heat medium, it is determined whether heating of the heat medium is required.

[0034] In step S4, the air conditioner controller 8 determines whether the outside air temperature of the vehicle detected by the outside air temperature sensor 101 is equal to or lower than any arbitrarily set low temperature (e.g., 5°C). If the air conditioner controller 8 determines that the outside air temperature is not lower than the arbitrarily set temperature (e.g., 5°C) (i.e., higher than the arbitrarily set temperature) (No in step S4), the process proceeds to step S5. If it is determined that the outside air temperature is equal to or lower than the arbitrarily set temperature (e.g., 5°C) (Yes in step S4), the process proceeds to step S7.

[0035] In step S5, the air conditioner controller 8 determines whether the temperature of the heat medium (coolant) detected by the heat medium temperature sensor 102 is higher than the outside air temperature of the vehicle detected by the outside air temperature sensor 101. If the air conditioner controller 8 determines that the temperature of the heat medium is higher than the outside air temperature (Yes in step S5), it is determined that the heat medium can be circulated without heating to evaporate the liquid refrigerant, and the process proceeds to step S9. If it is determined that the temperature of the heat medium is not higher than the outside air temperature (i.e., lower than the outside air temperature) (No in step S5), the process proceeds to step S6 to consider whether heating of the heat medium is required.

[0036] In step S6, the air conditioner controller 8 determines whether the temperature of the heat medium (coolant) detected by the heat medium temperature sensor 102 is higher than the temperature of the refrigerant detected by the refrigerant temperature sensor 103 (or the refrigerant temperature estimated based on the refrigerant pressure detected by the refrigerant pressure sensor 104). If the air conditioner controller 8 determines that the heat medium temperature is higher than the refrigerant temperature (Yes in step S6), it is determined that heating of the heat medium is not required, and the process proceeds to step S9. If it is determined that the heat medium temperature is not higher than the refrigerant temperature (i.e., below the refrigerant temperature) (No in step S6), it is determined that heating of the heat medium is required, and the process proceeds to step S8.

[0037] In step S7, the air conditioner controller 8 determines whether the temperature of the heat medium (coolant) detected by the heat medium temperature sensor 102 is equal to or lower than a temperature that is α °C (e.g., α = 2 °C) higher than any temperature in step S4 (e.g., 5 °C) (any temperature + α °C) (e.g., 7 °C). If the air conditioner controller 8 determines that the heat medium temperature is equal to or lower than the any temperature + α °C (e.g., 7 °C) (Yes in step S7), it is determined that heating of the heat medium is required, and the process proceeds to step S8. If it is determined that the heat medium temperature is not lower than the any temperature + α °C (higher than the any temperature + α °C) (No in step S7), it is determined that heating of the heat medium is not required, and the process proceeds to step S9.

[0038] In step S8, the air conditioner controller 8 operates the heat medium heater 7, thereby heating the heat medium flowing into the heat medium side flow path 14B of the cooling heat exchanger 14.

[0039] In step S9, the air conditioner controller 8 executes the liquid refrigerant evaporation mode. In this liquid refrigerant evaporation mode, the air conditioner controller 8 controls to connect the inlet in the three-way valve 43 and the outlet on the cooling heat exchanger 14 side by closing the valve on the external gas heat medium heat exchanger 40 side in the three-way valve 43 and opening the valves on the motor unit 6 side and the cooling heat exchanger 14 side in the three-way valve 43. At the same time, the air conditioner controller 8 operates the circulation pumps 41 and 42.

[0040] As a result, in the heat medium circuit 4, the heat medium whose temperature has risen by the battery 5 (and also the heat medium whose temperature has risen in the case of operating the heat medium heater 7 in step S8) and the heat medium whose temperature has risen by the motor unit 6 are mixed before flowing into the heat medium side flow path 14B of the cooling heat exchanger 14. That is, the heat medium whose temperature has risen by the battery 5 (or the battery 5 and the heat medium heater 7) and the motor unit 6 flows into the heat medium side flow path 14B of the cooling heat exchanger 14.

[0041] Using the high-temperature heat medium flowing into the heat medium side flow path 14B, the liquid refrigerant staying in the refrigerant side flow path 14A is heat-exchanged and evaporated. Thus, in the liquid refrigerant evaporation mode, by dissipating the heat recovered by the heat medium circuit 4 to the liquid refrigerant in the cooling heat exchanger 14, the liquid refrigerant is evaporated.

[0042] In addition, in this step S9, the air-conditioning controller 8 performs control to fully close the pressure reducing device 26 provided on the refrigerant pipe R11 and the pressure reducing device 25 provided on the refrigerant pipe R7. Thereby, during the execution of the liquid refrigerant evaporation mode, the refrigerant evaporated by heat exchange with the heat medium in the cooling heat exchanger 14 does not flow to the second heat exchanger 12 through the refrigerant pipe R11 and the refrigerant pipe R7, but can flow to the accumulator 10 through the refrigerant pipe R12. After the processing of step S9 by the air-conditioning controller 8 is completed, Figure 3 a series of operation processes

[0043] In addition, the execution control operation of the liquid refrigerant evaporation mode (evaporation operation) performed by the air-conditioning controller 8 (control device) is not limited to Figure 3 the example of Figure 3 For example, the air-conditioning controller 8 can also replace Figure 3 steps S5 and S6, and perform the next process as step S105, and other processes are the same as Figure 3 In step S105, the air-conditioning controller 8 determines whether the outside air temperature of the vehicle detected by the outside air temperature sensor 101 is higher than the refrigerant temperature detected by the refrigerant temperature sensor 103 (or the refrigerant temperature estimated based on the refrigerant pressure detected by the refrigerant pressure sensor 104). If the air-conditioning controller 8 determines that the outside air temperature is higher than the refrigerant temperature (yes in step S105), it determines that heating of the heat medium is not required and enters step S9. If it determines that the heat medium temperature is not higher than the refrigerant temperature (i.e., below the refrigerant temperature) (no in step S105), it determines that heating of the heat medium is required and enters step S8.

[0044] In addition, for example, in Figure 3 the example of Figure 3 the air-conditioning controller 8 performs the process of step S6 after step S5, but instead, it can also perform the process of step S5 after step S6.

[0045] Next, use Figure 4Describe the stop control operation of the liquid refrigerant evaporation mode performed by the air-conditioning controller 8 (control device), which is one of the operations of the vehicle air-conditioning device 1. In step S11, the air-conditioning controller 8 determines whether the current time is in the middle of the liquid refrigerant evaporation mode. If the air-conditioning controller 8 determines that the current time is in the middle of the liquid refrigerant evaporation mode (Yes in step S11), it proceeds to step S12. If it determines that the current time is not in the middle of the liquid refrigerant evaporation mode (No in step S11), it ends Figure 4 a series of operation processes.

[0046] In step S12, the air-conditioning controller 8 determines whether the heat medium heater 7 is operating. If the air-conditioning controller 8 determines that the heat medium heater 7 is operating (Yes in step S12), it proceeds to step S13 to consider whether it is necessary to continue heating the heat medium. If it determines that the heat medium heater 7 is not operating (No in step S12), it proceeds to step S15 to consider whether it is necessary to continue executing the liquid refrigerant evaporation mode.

[0047] In step S13, the air-conditioning controller 8 determines whether the heat medium temperature detected by the heat medium temperature sensor 102 is above a specific temperature (e.g., 35°C). If it determines that it is above the specific temperature (Yes in step S13), it determines that it is not necessary to continue heating the heat medium and proceeds to step S14. If it determines that it is not above the specific temperature (less than the specific temperature) (No in step S13), it proceeds to step S15 while continuing to heat the heat medium.

[0048] In step S14, the air-conditioning controller 8 stops the operation of the heat medium heater 7. At this time, the liquid refrigerant evaporation mode becomes a state where only the circulation pumps 41 and 42 are operating.

[0049] In step S15, the air-conditioning controller 8 determines whether the difference between the outside air temperature detected by the outside air temperature sensor 101 and the heat medium temperature detected by the heat medium temperature sensor 102 is below a specified value (e.g., 10°C). If it determines that it is below the specified value (Yes in step S15), it determines that it is not necessary to continue executing the liquid refrigerant evaporation mode and proceeds to step S17. If it determines that it is not below the specified value (greater than the specified value) (No in step S15), it considers whether it is necessary to continue executing the liquid refrigerant evaporation mode.

[0050] In step S16, the air conditioner controller 8 determines whether the execution time (evaporation operation time) of the liquid refrigerant evaporation mode is equal to or longer than a specified time (e.g., 5 minutes). If the determination is that it is equal to or longer than the specified time ("Yes" in step S16), it is determined that there is no need to continue executing the liquid refrigerant evaporation mode, and the process proceeds to step S17. If the determination is that it is not equal to or longer than the specified time (less than the specified time) ("No" in step S16), a series of operation processes Figure 4 are ended in order to continue executing the liquid refrigerant evaporation mode.

[0051] In step S17, the air conditioner controller 8 stops the liquid refrigerant evaporation mode (evaporation operation). Specifically, the air conditioner controller 8 stops the operation of the circulation pumps 41 and 42. At the same time, while the valve on the motor unit 6 side in the three-way valve 43 is open, the air conditioner controller 8 opens the valve on the external gas heat medium heat exchanger 40 side in the three-way valve 43 and closes the valve on the cooling heat exchanger 14 side, thereby performing control to put the inlet in the three-way valve 43 and the outlet on the external gas heat medium heat exchanger 40 side in a communicating state.

[0052] In addition, in this step S17, the air conditioner controller 8 performs control to fully open the pressure reducing device 26 provided on the refrigerant pipe R11 and the pressure reducing device 25 provided on the refrigerant pipe R7. Thereby, after the liquid refrigerant evaporation mode ends, the refrigerant can flow through the refrigerant pipe R11 and the refrigerant pipe R7 to the second heat exchanger 12. After the processing in step S17 by the air conditioner controller 8 is completed, a series of operation processes Figure 4 are ended.

[0053] According to the vehicle air conditioner device 1 of the present embodiment described above, it is possible to suppress the following situation: that is, when the flow path of the refrigerant circuit R is switched from passing through the cooling heat exchanger (refrigerant heat medium heat exchanger) 14 to bypassing the cooling heat exchanger 14 to stop the flow of the refrigerant to the cooling heat exchanger 14 (when the operation mode of the refrigerant circuit R is switched), or after the cooling operation mode is executed and the refrigerant circuit R stops and then the refrigerant circuit R restarts, the state where the liquid refrigerant stays in the cooling heat exchanger 14. Thus, the vehicle air conditioner device 1 can prevent the refrigerant circuit R from becoming a state of having too little refrigerant (a state where the amount of circulated refrigerant decreases) when operating the refrigerant circuit R in the flow path bypassing the cooling heat exchanger 14 or when restarting the refrigerant circuit R, etc.

[0054] As described above, the present embodiment has been described in detail with reference to the drawings, but the specific structure is not limited to the above example, and even design changes and the like within the scope of not departing from the gist of the present invention are included in the present invention.

[0055] For example, the use of the above-described embodimentFigure 3 , Figure 4 In the processing steps (steps S1, S3 to S7, S13, S15, S16, S105) for comparing the magnitudes of the described temperature or time, "above" is set to "higher (longer)", "less than" can be set to "below", "higher" can be set to "above", and "below" can be set to "less than".

[0056] In addition, for example, in the liquid refrigerant evaporation mode in the above-described embodiment, the air-conditioning controller 8 operates the circulation pumps 41 and 42 to mix the heat medium whose temperature has risen through the motor unit 6 and the heat medium whose temperature has risen through the battery 5 (the heat medium whose temperature has also risen in the case of operating the heat medium heater 7), and causes the mixture to flow into the cooling heat exchanger 14. However, as described above, it is not limited to the example in which the heat recovered from the battery 5 and the heat recovered from the motor unit 6 are combined and the cooling heat exchanger 14 absorbs the heat. It is also possible for the heat recovered from the battery 5 and the heat recovered from the motor unit 6 to separately absorb heat by the cooling heat exchanger 14.

[0057] For example, in the liquid refrigerant evaporation mode, when heating of the heat medium is not required, the circulation pump 42 may not be operated and the circulation pump 41 may be operated, and only the heat medium whose temperature has risen through the motor unit 6 may be caused to flow into the cooling heat exchanger 14.

[0058] For example, in the liquid refrigerant evaporation mode, when heating of the heat medium is not required, the circulation pump 41 may not be operated and the circulation pump 42 may be operated, and only the heat medium whose temperature has risen through the battery 5 may be caused to flow into the cooling heat exchanger 14.

[0059] In addition, in the liquid refrigerant evaporation mode, when heating of the heat medium is required, the circulation pump 41 may not be operated and the circulation pumps 42 and the heat medium heater 7 may be operated, and only the heat medium whose temperature has risen through the heat medium heater 7 and the battery 5 may be caused to flow into the cooling heat exchanger 14. Reference Numeral Explanation

[0060] 1 Vehicle air-conditioning device 2 Compressor (electric compressor) 10 Receiver 11 First heat exchanger 12 Second heat exchanger 13 Outdoor heat exchanger 14 Refrigerant heat medium heat exchanger (cooling heat exchanger) 14A Refrigerant side flow path 14B Refrigerant side flow path 20, 21 Flow path switching valves (solenoid valves) 22, 23 Check valves 24 - 26 Pressure reducing device (expansion valve) 3 HVAC unit 30 Air circulation path 31 Air outlet 32 Indoor blower 33 Internal gas inlet 34 External gas inlet 35 Inlet switching damper 36 Air mixing damper 4 Heat medium circuit 4T tank 40 External gas heat medium heat exchanger 41, 42 Circulation pumps 43 Three - way valve 5 Battery 6 Motor unit 7 Heat medium heater 8 Air - conditioner controller (control device) 9 Vehicle controller R Refrigerant circuit R1 - R12 Refrigerant pipes TS Temperature sensor PTS Refrigerant temperature sensor and refrigerant pressure sensor 100 Various sensors 101 External gas temperature sensor 102 Heat medium temperature sensor 103 Refrigerant temperature sensor 104 Refrigerant pressure sensor 105 Internal gas temperature sensor.

Claims

1. A vehicle air conditioning device is a vehicle air conditioning device that uses the heat dissipation and heat absorption of a refrigerant circuit to condition the air in the passenger compartment, characterized in that, Comprising: A refrigerant heat medium heat exchanger that exchanges heat between the refrigerant in the refrigerant circuit and the heat medium; A heat medium circuit that circulates the heat medium; And A control device that controls the operations of the refrigerant circuit and the heat medium circuit, The control device executes a liquid refrigerant evaporation mode that causes the liquid refrigerant to evaporate when it is presumed that liquid refrigerant remains in the refrigerant heat medium heat exchanger.

2. The vehicle air conditioning device according to claim 1, characterized in that In the liquid refrigerant evaporation mode, The heat recovered by the heat medium circuit is dissipated to the liquid refrigerant in the refrigerant heat medium heat exchanger.

3. The vehicle air conditioning device according to claim 1, characterized in that The liquid refrigerant evaporation mode is executed when the temperature of the heat medium in the heat medium circuit is higher than the external gas temperature.

4. The vehicle air conditioning device according to claim 1, characterized in that The presumption that the liquid refrigerant remains in the refrigerant heat medium heat exchanger is made when the external gas temperature is below a set threshold value and the refrigerant heat medium heat exchanger performs an operation of absorbing heat from the heat medium by the refrigerant.

5. The vehicle air conditioning device according to claim 1, characterized in that The presumption that the liquid refrigerant remains in the refrigerant heat medium heat exchanger is made when the external gas temperature is below a set threshold value and the external gas temperature is below the temperature inside the vehicle compartment.

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