JP2017156019A - Vehicle air conditioning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle air conditioning device that detects a refrigerant leakage with age at an earliest possible phase to protect a compressor.SOLUTION: The vehicle air conditioning device includes: a compressor 2; a radiator 4 for causing a refrigerant to radiate heat; an outdoor heat exchanger 7 provided on the outside of vehicle interior; and an accumulator 12 connected on a refrigerant-suction side of the compressor. The vehicle air conditioning device causes the refrigerant discharged from the compressor to radiate heat from the radiator to heat the vehicle interior and causes the outdoor heat exchanger to absorb heat. A controller detects an amount of liquid refrigerant in the accumulator and determines any occurrence of refrigerant leakage based on the amount of liquid refrigerant.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat pump type air conditioner that air-conditions a vehicle interior of a vehicle, and more particularly to an air conditioner that can be applied to a hybrid vehicle and an electric vehicle.

  Hybrid vehicles and electric vehicles have come into widespread use due to the emergence of environmental problems in recent years. As an air conditioner that can be applied to such a vehicle, a compressor that compresses and discharges the refrigerant, a radiator that is provided on the vehicle interior side and dissipates the refrigerant, and is provided on the vehicle interior side. A heat absorber that absorbs the refrigerant and an outdoor heat exchanger that is provided outside the passenger compartment to dissipate or absorb heat from the passenger compartment, dissipate the refrigerant discharged from the compressor in the radiator, and dissipate the refrigerant dissipated in the radiator Heating operation that absorbs heat in the outdoor heat exchanger, dehumidifying heating operation and dehumidifying cooling operation that cause the refrigerant discharged from the compressor to dissipate heat in the radiator, and the refrigerant that dissipated heat in the radiator absorbs heat in the heat absorber, and discharge from the compressor A system has been developed that switches the cooling operation to dissipate the generated refrigerant in the outdoor heat exchanger and absorb the heat in the heat absorber.

  In addition, an accumulator is provided on the refrigerant suction side of the compressor, gas and liquid are separated by temporarily storing the refrigerant in the accumulator, and liquid return to the compressor is prevented by sucking the gas refrigerant into the compressor. It was made to suppress (for example, refer patent document 1).

JP 2012-228945 A

  Here, the refrigerant gradually leaks from the refrigerant circuit of the vehicle air conditioner as time elapses, but conventionally, there is nothing other than protecting and stopping the compressor after most of the refrigerant disappears from the circuit. It was.

  The present invention has been made to solve the conventional technical problem, and provides a vehicle air conditioner that can detect aged refrigerant leakage at the earliest possible stage and protect the compressor. For the purpose.

  The vehicle air conditioner of the present invention heats the compressor that compresses the refrigerant, the air flow passage through which the air supplied to the vehicle interior flows, and the air that dissipates the refrigerant and is supplied from the air flow passage to the vehicle interior. A heat radiator, an outdoor heat exchanger provided outside the passenger compartment, an accumulator connected to the refrigerant suction side of the compressor, and a control device, and at least the refrigerant discharged from the compressor by the control device After the heat is dissipated by the radiator and the refrigerant that has been radiated is decompressed, the outdoor heat exchanger absorbs heat to heat the vehicle interior, and the control device detects the amount of liquid refrigerant in the accumulator. The occurrence of refrigerant leakage is determined based on the amount of the liquid refrigerant.

  In the vehicle air conditioner according to the second aspect of the present invention, in the above invention, the control device is based on the difference TXO-Ts between the temperature TXO of the outdoor heat exchanger and the suction refrigerant temperature Ts of the compressor. When becomes smaller than a predetermined value, it is determined that refrigerant leakage has occurred.

  According to a third aspect of the present invention, there is provided a vehicular air conditioner according to the first aspect of the present invention, wherein the control device determines that the refrigerant leaks when the superheat degree SH exceeds a predetermined value based on the superheat degree SH of the refrigerant sucked into the compressor. It is characterized in that it is determined that occurrence has occurred.

  A vehicle air conditioner according to a fourth aspect of the present invention is characterized in that, in each of the above inventions, the control device performs a predetermined notification operation when it is determined that refrigerant leakage has occurred.

  A compressor for compressing the refrigerant, an air flow passage through which air to be supplied to the vehicle interior flows, a radiator for heating the air to be radiated from the refrigerant and supplied to the vehicle interior from the air flow passage, and provided outside the vehicle interior Provided with an outdoor heat exchanger, an accumulator connected to the refrigerant suction side of the compressor, and a control device, and at least the refrigerant discharged from the compressor is radiated by the heat radiator by the control device and radiated. In a vehicle air conditioner that depressurizes the refrigerant and then absorbs heat with an outdoor heat exchanger to heat the vehicle interior, if the refrigerant gradually leaks, the amount of liquid refrigerant that accumulates in the accumulator decreases. Come.

  Therefore, in the present invention, since the control device detects the amount of liquid refrigerant in the accumulator and determines the occurrence of refrigerant leakage based on the amount of liquid refrigerant, the refrigerant gradually leaks. In addition, it is possible to determine that refrigerant leakage has occurred at an early stage, and to avoid the inconvenience that causes serious damage to the compressor.

  In this case, since the refrigerant discharged from the outdoor heat exchanger is stored in the accumulator, the temperature of the liquid refrigerant in the accumulator is the temperature of the outdoor heat exchanger (TXO). Further, since the oil must be returned from the accumulator to the compressor, the refrigerant exiting from the accumulator partially includes liquid refrigerant. Therefore, when sufficient liquid refrigerant is stored in the accumulator, more liquid refrigerant exits the accumulator, but the liquid refrigerant exiting the accumulator absorbs heat from the surroundings and evaporates.

  Then, the temperature will decrease due to the pressure loss with the saturation temperature, but if the amount of liquid refrigerant in the accumulator decreases as a result of refrigerant leakage, less liquid refrigerant will exit the accumulator, or However, since it hardly goes out, the temperature of the refrigerant sucked into the compressor (suction refrigerant temperature Ts) rises due to the influence of heat from the surroundings.

  Therefore, as in the invention of claim 2, the control device is configured such that the difference TXO-Ts becomes smaller than a predetermined value based on the difference TXO-Ts between the temperature TXO of the outdoor heat exchanger and the suction refrigerant temperature Ts of the compressor. In this case, it is possible to accurately determine the occurrence of refrigerant leakage by determining that refrigerant leakage has occurred, and it is not necessary to provide a sensor or the like that directly detects the amount of liquid refrigerant in the accumulator. .

  The difference TXO-Ts is also correlated with the superheat degree SH of the refrigerant sucked into the compressor. The greater the difference TXO-Ts, the smaller the superheat degree SH, and the smaller the difference TXO-Ts, the superheat degree SH. Will grow. Therefore, as in the third aspect of the invention, the control device may determine that refrigerant leakage has occurred when the superheat degree SH is greater than a predetermined value based on the superheat degree SH of the refrigerant sucked into the compressor. It becomes possible to accurately determine the occurrence of refrigerant leakage. Similarly, there is no need to provide a sensor or the like that directly detects the amount of liquid refrigerant in the accumulator.

  When the control device determines that refrigerant leakage has occurred as in the fourth aspect of the invention, by executing a predetermined notification operation, the user is warned of the occurrence of refrigerant leakage and prompt action is taken. It will be able to encourage.

It is a block diagram of the air conditioning apparatus for vehicles of one Embodiment to which this invention is applied (heating mode, dehumidification heating mode, dehumidification cooling mode, and cooling mode). It is a block diagram of the electric circuit of the controller of the vehicle air conditioner of FIG. It is a block diagram at the time of the MAX cooling mode (maximum cooling mode) of the vehicle air conditioner of FIG. It is a schematic sectional drawing of the accumulator of the vehicle air conditioner of FIG. FIG. 2 is a Ph diagram in a heating mode of the vehicle air conditioner of FIG. 1. It is another Ph diagram in the heating mode of the vehicle air conditioner of FIG. It is a figure which shows the relationship between the difference TXO-Ts of the outdoor heat exchanger temperature TXO of the vehicle air conditioner of FIG. 1, and the suction refrigerant temperature Ts, and refrigerant | coolant filling amount. It is a figure which shows the relationship between the difference TXO-Ts of the outdoor heat exchanger temperature TXO of the vehicle air conditioner of FIG. 1, and the suction refrigerant temperature Ts, and the superheat degree SH of the refrigerant | coolant sucked in by a compressor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a configuration diagram of a vehicle air conditioner 1 according to an embodiment of the present invention. A vehicle according to an embodiment to which the present invention is applied is an electric vehicle (EV) in which an engine (internal combustion engine) is not mounted, and travels by driving an electric motor for traveling with electric power charged in a battery. Yes (both not shown), the vehicle air conditioner 1 of the present invention is also driven by the power of the battery. That is, the vehicle air conditioner 1 of the embodiment performs a heating mode by a heat pump operation using a refrigerant circuit in an electric vehicle that cannot be heated by engine waste heat, and further includes a dehumidifying heating mode, a dehumidifying cooling mode, a cooling mode, And each operation mode of MAX cooling mode (maximum cooling mode) is selectively performed.

  The present invention is effective not only for electric vehicles but also for so-called hybrid vehicles that use an engine and an electric motor for traveling, and is also applicable to ordinary vehicles that run on an engine. Needless to say.

  The vehicle air conditioner 1 according to the embodiment performs air conditioning (heating, cooling, dehumidification, and ventilation) in a vehicle interior of an electric vehicle, and includes an electric compressor 2 that compresses refrigerant and vehicle interior air. Is provided in the air flow passage 3 of the HVAC unit 10 through which air is circulated, and the high-temperature and high-pressure refrigerant discharged from the compressor 2 flows in through the refrigerant pipe 13G, and dissipates the refrigerant into the vehicle compartment. And an outdoor expansion valve 6 comprising an electric valve that decompresses and expands the refrigerant during heating, and functions as a radiator during cooling and functions as a radiator during heating, and exchanges heat between the refrigerant and the outside air so as to function as an evaporator during heating. An outdoor heat exchanger 7 that performs the above operation, an indoor expansion valve 8 that is an electric valve that decompresses and expands the refrigerant, and a heat absorber 9 that is provided in the air flow passage 3 and absorbs heat from outside the vehicle interior to the refrigerant during cooling and dehumidification. And accumulator 12 etc. Are sequentially connected by a refrigerant pipe 13, the refrigerant circuit R is formed.

  The refrigerant circuit R is filled with a predetermined amount of refrigerant and lubricating oil. The outdoor heat exchanger 7 is provided with an outdoor blower 15. The outdoor blower 15 exchanges heat between the outside air and the refrigerant by forcibly passing outside air through the outdoor heat exchanger 7, so that the outdoor air blower 15 can also be used outdoors even when the vehicle is stopped (that is, the vehicle speed is 0 km / h). It is comprised so that external air may be ventilated by the heat exchanger 7. FIG.

  The outdoor heat exchanger 7 has a receiver dryer unit 14 and a supercooling unit 16 in order on the downstream side of the refrigerant, and the refrigerant pipe 13A exiting from the outdoor heat exchanger 7 includes a dehumidifying heating mode, a dehumidifying cooling mode, a cooling mode, The refrigerant pipe 13B on the outlet side of the supercooling section 16 is connected to the inlet side of the heat absorber 9 via the indoor expansion valve 8 via the electromagnetic valve 17 for cooling opened in the MAX cooling mode. It is connected to the. In addition, the receiver dryer part 14 and the supercooling part 16 structurally constitute a part of the outdoor heat exchanger 7.

  The refrigerant pipe 13B between the subcooling section 16 and the indoor expansion valve 8 is provided in a heat exchange relationship with the refrigerant pipe 13C on the outlet side of the heat absorber 9, and constitutes an internal heat exchanger 19 together. Thus, the refrigerant flowing into the indoor expansion valve 8 through the refrigerant pipe 13B is cooled (supercooled) by the low-temperature refrigerant that has exited the heat absorber 9.

  Further, the refrigerant pipe 13A exiting from the outdoor heat exchanger 7 is branched into a refrigerant pipe 13D, and the branched refrigerant pipe 13D is connected to the internal heat exchanger via a heating electromagnetic valve 21 opened in the heating mode. 19 is connected to a refrigerant pipe 13 </ b> C on the downstream side. The refrigerant pipe 13 </ b> C is connected to the accumulator 12, and the accumulator 12 is connected to the refrigerant suction side of the compressor 2. Further, the refrigerant pipe 13E on the outlet side of the radiator 4 is connected to the inlet side of the outdoor heat exchanger 7 via the outdoor expansion valve 6.

  In addition, the refrigerant pipe 13G between the discharge side of the compressor 2 and the inlet side of the radiator 4 is reheated in the heating mode, the dehumidifying cooling mode, and the cooling mode, and closed in the dehumidifying heating mode and the MAX cooling mode. An electromagnetic valve 30 is provided. In this case, the refrigerant pipe 13G is branched into a bypass pipe 35 on the upstream side of the electromagnetic valve 30, and the bypass pipe 35 is opened in the dehumidifying heating mode and the MAX cooling mode, and is heated, dehumidified and cooled, and cooled. The refrigerant pipe 13E is connected to the downstream side of the outdoor expansion valve 6 through a bypass electromagnetic valve 40 that is closed in the mode. Bypass pipe 45, solenoid valve 30 and solenoid valve 40 constitute bypass device 45.

  Since the bypass device 45 is configured by the bypass pipe 35, the electromagnetic valve 30, and the electromagnetic valve 40, the dehumidifying heating mode or the MAX for allowing the refrigerant discharged from the compressor 2 to directly flow into the outdoor heat exchanger 7 as will be described later. Switching between the cooling mode and the heating mode in which the refrigerant discharged from the compressor 2 flows into the radiator 4, the dehumidifying cooling mode, and the cooling mode can be performed smoothly.

  The air flow passage 3 on the air upstream side of the heat absorber 9 is formed with each of an outside air inlet and an inside air inlet (represented by the inlet 25 in FIG. 1). 25 is provided with a suction switching damper 26 for switching the air introduced into the air flow passage 3 between the inside air (inside air circulation mode) which is air inside the passenger compartment and the outside air (outside air introduction mode) which is outside the passenger compartment. Yes. Furthermore, an indoor blower (blower fan) 27 for supplying the introduced inside air or outside air to the air flow passage 3 is provided on the air downstream side of the suction switching damper 26.

  Moreover, in FIG. 1, 23 is an auxiliary heater as an auxiliary heating device provided in the vehicle air conditioner 1 of the embodiment. The auxiliary heater 23 of the embodiment is composed of a PTC heater which is an electric heater, and is provided in the air flow passage 3 on the air upstream side of the radiator 4 with respect to the air flow in the air flow passage 3. Yes. When the auxiliary heater 23 is energized and generates heat, the air in the air flow passage 3 flowing into the radiator 4 through the heat absorber 9 is heated. In other words, the auxiliary heater 23 serves as a so-called heater core, which heats or complements the passenger compartment.

  In addition, air in the air flow passage 3 on the upstream side of the auxiliary heater 23 flows into the air flow passage 3 and assists air (inside air or outside air) in the air flow passage 3 after passing through the heat absorber 9. An air mix damper 28 is provided for adjusting the ratio of ventilation through the heater 23 and the radiator 4. Further, FOOT (foot), VENT (vent), and DEF (def) outlets (represented by the outlet 29 as a representative in FIG. 1) are formed in the air flow passage 3 on the air downstream side of the radiator 4. The air outlet 29 is provided with an air outlet switching damper 31 that performs switching control of air blowing from the air outlets.

Next, in FIG. 2, reference numeral 32 denotes a controller (ECU) as a control device composed of a microcomputer which is an example of a computer provided with a processor. The controller 32 detects the outside air temperature (Tam) of the vehicle. The outside air temperature sensor 33 for detecting the outside air humidity, the HVAC suction temperature sensor 36 for detecting the temperature of the air sucked into the air flow passage 3 from the suction port 25, and the air (inside air) in the passenger compartment. An inside air temperature sensor 37 that detects the temperature, an inside air humidity sensor 38 that detects the humidity of the air in the passenger compartment, an indoor CO ₂ concentration sensor 39 that detects the carbon dioxide concentration in the passenger compartment, and an air outlet from the outlet 29 And a discharge pressure sensor 41 for detecting the discharge refrigerant pressure (discharge pressure Pd) of the compressor 2. 42, a discharge temperature sensor 43 that detects the refrigerant discharge temperature of the compressor 2, a suction pressure sensor 44 that detects the suction refrigerant pressure of the compressor 2, and the temperature of the refrigerant that comes out of the accumulator 12 and is sucked into the compressor 2. A suction temperature sensor 55 for detecting a certain suction refrigerant temperature (Ts) and a radiator for detecting the temperature of the radiator 4 (the temperature of the air passing through the radiator 4 or the temperature of the radiator 4 itself: the radiator temperature TH). A temperature sensor 46, a radiator pressure sensor 47 for detecting the refrigerant pressure of the radiator 4 (the pressure of the refrigerant in the radiator 4 or immediately after leaving the radiator 4: the radiator pressure PCI), and the heat absorber 9. A heat absorber temperature sensor 48 that detects the temperature (the temperature of the air that has passed through the heat absorber 9 or the temperature of the heat absorber 9 itself: the heat absorber temperature Te), and the refrigerant pressure of the heat absorber 9 (in the heat absorber 9 or the heat absorption). The refrigerant pressure immediately after leaving the vessel 9) An endothermic pressure sensor 49, a photosensor-type solar sensor 51 for detecting the amount of solar radiation into the passenger compartment, a vehicle speed sensor 52 for detecting the moving speed (vehicle speed) of the vehicle, set temperature and driving An air conditioning (air conditioner) operation unit 53 for setting the mode switching, and the temperature of the outdoor heat exchanger 7 (the temperature of the refrigerant immediately after coming out of the outdoor heat exchanger 7 (flowing into the accumulator 12 in the heating mode described later) The temperature of the refrigerant to be cooled: the outdoor heat exchanger temperature sensor 54 for detecting the outdoor heat exchanger temperature TXO) and the refrigerant pressure of the outdoor heat exchanger 7 (in the outdoor heat exchanger 7 or from the outdoor heat exchanger 7) Each output of the outdoor heat exchanger pressure sensor 56 that detects the pressure of the refrigerant immediately after that: the outdoor heat exchanger pressure PXO) is connected to the input of the controller 32. Air temperature immediately after being heated by motor 23, or an auxiliary heater 23 itself temperature is also connected the output of the auxiliary heater temperature sensor 50 for detecting the auxiliary heater temperature TPTC).

  On the other hand, the output of the controller 32 includes the compressor 2, the outdoor blower 15, the indoor blower (blower fan) 27, the suction switching damper 26, the air mix damper 28, the outlet switching damper 31, and the outdoor expansion. The solenoid valve, the indoor expansion valve 8, the auxiliary heater 23, the solenoid valve 30 (for reheating), the solenoid valve 17 (for cooling), the solenoid valve 21 (for heating), and the solenoid valve 40 (for bypass) are connected. Has been. And the controller 32 controls these based on the output of each sensor, and the setting input in the air-conditioning operation part 53. FIG.

  Next, the operation of the vehicle air conditioner 1 having the above-described configuration will be described. In the embodiment, the controller 32 switches between the operation modes of the heating mode, the dehumidifying heating mode, the dehumidifying cooling mode, the cooling mode, and the MAX cooling mode. First, an outline of refrigerant flow and control in each operation mode will be described.

(1) Heating mode When the heating mode is selected by the controller 32 (auto mode) or by the manual operation (manual mode) to the air conditioning operation unit 53, the controller 32 opens the solenoid valve 21 (for heating) and opens the solenoid valve. Close 17 (for cooling). Further, the electromagnetic valve 30 (for reheating) is opened, and the electromagnetic valve 40 (for bypass) is closed.

  Then, the compressor 2 and each of the blowers 15 and 27 are operated, and the air mix damper 28 is blown out from the indoor blower 27 and passes through the heat absorber 9 as shown by a broken line in FIG. It is assumed that air is passed through the auxiliary heater 23 and the radiator 4. As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the electromagnetic valve 30. Since the air in the airflow passage 3 is passed through the radiator 4, the air in the airflow passage 3 is converted into the high-temperature refrigerant in the radiator 4 (when the auxiliary heater 23 operates, the auxiliary heater 23 and the radiator 4. On the other hand, the refrigerant in the radiator 4 is cooled by being deprived of heat by the air, and is condensed and liquefied.

  The refrigerant liquefied in the radiator 4 exits the radiator 4 and then reaches the outdoor expansion valve 6 through the refrigerant pipe 13E. The refrigerant flowing into the outdoor expansion valve 6 is decompressed there and then flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 evaporates, and pumps up heat from the outside air that is ventilated by traveling or by the outdoor blower 15. That is, the refrigerant circuit R becomes a heat pump. Then, the low-temperature refrigerant exiting the outdoor heat exchanger 7 enters the accumulator 12 through the refrigerant pipe 13C through the refrigerant pipe 13A, the solenoid valve 21 and the refrigerant pipe 13D, and is gas-liquid separated there. Repeated circulation inhaled.

  Here, FIG. 4 shows a cross-sectional view of the accumulator 12. The accumulator 12 is a so-called gas-liquid separator for separating the liquid refrigerant and the gas refrigerant flowing in via the refrigerant pipe 13C, and has a tank 57 having upper and lower predetermined dimensions and a predetermined capacity inside, and the tank 57 The baffle plate 58 disposed in the upper part of the tank 57 and spaced apart from the side wall and the upper wall of the tank 57, and enters the inside from the upper wall of the tank 57, penetrates the baffle plate 58, and once reaches the bottom of the tank 57. The outlet pipe 61 is opened after being lowered, and the raised tip is opened below the baffle plate 58 with an interval.

  The lowermost part of the outlet pipe 61 is located immediately above the bottom wall of the tank 57 with a small clearance, and an oil return hole 62 formed of a small hole is formed at the lowermost part. Further, the upper end of the outlet pipe 61 exits from the upper wall of the tank 57 and is connected to the suction side of the compressor 2. Then, the refrigerant pipe 13 </ b> C enters from the upper wall of the tank 57 and opens on the upper side of the baffle plate 58.

  The gas refrigerant evaporated in the outdoor heat exchanger 7 and the non-evaporated liquid refrigerant pass through the refrigerant pipe 13A, the electromagnetic valve 21 and the refrigerant pipe 13D as described above and from the refrigerant pipe 13C to the tank 57 of the accumulator 12 as shown by the arrow in FIG. Get inside. The refrigerant in the gas-liquid mixed state flowing into the tank 57 first collides with the baffle plate 58 and spreads outward, and flows down between the outer edge of the baffle plate 58 and the tank 57 as shown by the arrows and into the lower part of the tank 57. To do.

  The liquid refrigerant is stored in the lower part of the tank 57, and the gas refrigerant and the gas refrigerant in which the liquid refrigerant has evaporated in the accumulator 12 pass through the gap between the tip of the outlet pipe 61 and the baffle plate 58 as shown by the arrows. After entering the outlet pipe 61 from the opening at the tip and flowing down, it rises again and exits from the accumulator 12. The tank 57 also stores oil (for lubricating the compressor 2) circulating in the refrigerant circuit R together with the refrigerant. A part of the oil and liquid refrigerant enters the outlet pipe 61 from the oil return hole 62 formed in the lowermost part of the outlet pipe 61 and rises and exits from the accumulator 12.

  Since the liquid refrigerant out of the refrigerant and oil that has come out of the accumulator 12 absorbs heat and evaporates from the outside in the process of reaching the compressor 2, only the gas refrigerant and oil are sucked into the compressor 2. The suction temperature sensor 55 detects the temperature of the refrigerant (suction refrigerant temperature Ts).

  Since the air heated by the radiator 4 (when the auxiliary heater 23 is operated, the auxiliary heater 23 and the radiator 4) is blown out from the outlet 29, the vehicle interior is thereby heated. In this case, the controller 32 calculates a target radiator pressure PCO (target value of the radiator pressure PCI) from a target radiator temperature TCO (target value of the radiator temperature TH) calculated from a target outlet temperature TAO described later, The number of revolutions of the compressor 2 is controlled based on the target radiator pressure PCO and the refrigerant pressure of the radiator 4 (radiator pressure PCI; high pressure of the refrigerant circuit R) detected by the radiator pressure sensor 47. Further, the controller 32 determines the valve opening degree of the outdoor expansion valve 6 based on the temperature of the radiator 4 (the radiator temperature TH) detected by the radiator temperature sensor 46 and the radiator pressure PCI detected by the radiator pressure sensor 47. And the supercooling degree SC of the refrigerant at the outlet of the radiator 4 (calculated from the radiator temperature TH and the radiator pressure PCI) is controlled to a predetermined target supercooling degree TGSC which is the target value. The target radiator temperature TCO is basically set to TCO = TAO, but a predetermined restriction on control is provided.

  Further, in this heating mode, when the heating capacity by the radiator 4 is insufficient with respect to the heating capacity required for the vehicle interior air conditioning, the controller 32 assists so that the shortage is supplemented by the heat generated by the auxiliary heater 23. The energization of the heater 23 is controlled. Thereby, comfortable vehicle interior heating is realized and frost formation of the outdoor heat exchanger 7 is also suppressed. At this time, since the auxiliary heater 23 is disposed on the air upstream side of the radiator 4, the air flowing through the air flow passage 3 is vented to the auxiliary heater 23 before the radiator 4.

  Here, when the auxiliary heater 23 is disposed on the air downstream side of the radiator 4, when the auxiliary heater 23 is configured by a PCT heater as in the embodiment, the temperature of the air flowing into the auxiliary heater 23 is determined by the radiator. 4, the resistance value of the PTC heater increases, the current value also decreases, and the heat generation amount decreases. However, by arranging the auxiliary heater 23 on the air upstream side of the radiator 4, Thus, the capacity of the auxiliary heater 23 composed of the PTC heater can be sufficiently exhibited.

(2) Dehumidification heating mode Next, in the dehumidification heating mode, the controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21. Further, the electromagnetic valve 30 is closed, the electromagnetic valve 40 is opened, and the valve opening degree of the outdoor expansion valve 6 is fully closed. Then, the compressor 2 and each of the blowers 15 and 27 are operated, and the air mix damper 28 is blown out from the indoor blower 27 and passes through the heat absorber 9 as shown by a broken line in FIG. It is assumed that air is passed through the auxiliary heater 23 and the radiator 4.

  Accordingly, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 to the refrigerant pipe 13G flows into the bypass pipe 35 without going to the radiator 4, passes through the electromagnetic valve 40, and is connected to the refrigerant pipe on the downstream side of the outdoor expansion valve 6. 13E. At this time, since the outdoor expansion valve 6 is fully closed, the refrigerant flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is cooled and condensed by running there or by the outside air ventilated by the outdoor blower 15. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 </ b> A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.

  The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 </ b> B, reaches the indoor expansion valve 8 through the internal heat exchanger 19. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 by the heat absorption action at this time is cooled, and moisture in the air condenses and adheres to the heat absorber 9, so that the air in the air flow passage 3 is cooled, and Dehumidified. The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 through the refrigerant pipe 13C, and repeats circulation that is separated into gas and liquid and sucked into the compressor 2 as described above.

  At this time, since the valve opening degree of the outdoor expansion valve 6 is fully closed, it is possible to suppress or prevent inconvenience that the refrigerant discharged from the compressor 2 flows backward from the outdoor expansion valve 6 into the radiator 4. It becomes. Thereby, the fall of a refrigerant | coolant circulation amount can be suppressed or eliminated and air-conditioning capability can be ensured now. Further, in this dehumidifying and heating mode, the controller 32 energizes the auxiliary heater 23 to generate heat. As a result, the air cooled and dehumidified by the heat absorber 9 is further heated in the process of passing through the auxiliary heater 23 and the temperature rises, so that the dehumidifying heating in the passenger compartment is performed.

  The controller 32 controls the rotational speed of the compressor 2 on the basis of the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO that is the target value, and the auxiliary heater temperature. By controlling the energization (heat generation) of the auxiliary heater 23 based on the auxiliary heater temperature Tptc detected by the sensor 50 and the target radiator temperature TCO described above, while appropriately cooling and dehumidifying the air in the heat absorber 9, A decrease in the temperature of the air blown from the outlet 29 into the passenger compartment by heating by the auxiliary heater 23 is accurately prevented.

  As a result, it is possible to control the temperature to an appropriate heating temperature while dehumidifying the air blown into the vehicle interior, and it is possible to realize comfortable and efficient dehumidification heating in the vehicle interior. Further, as described above, in the dehumidifying heating mode, the air mix damper 28 is in a state where all the air in the air flow passage 3 is passed through the auxiliary heater 23 and the radiator 4, so that the air passing through the heat absorber 9 is efficiently assisted. Heating by the heater 23 can improve the energy saving performance, and the controllability of the dehumidifying heating air conditioning can also be improved.

  In addition, since the auxiliary heater 23 is disposed on the air upstream side of the radiator 4, the air heated by the auxiliary heater 23 passes through the radiator 4. In this dehumidifying heating mode, the refrigerant is supplied to the radiator 4. Therefore, the disadvantage that the radiator 4 absorbs heat from the air heated by the auxiliary heater 23 is also eliminated. That is, the temperature of the air blown out into the vehicle compartment by the radiator 4 is suppressed, and the COP is improved.

(3) Dehumidifying and Cooling Mode Next, in the dehumidifying and cooling mode, the controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21. Further, the electromagnetic valve 30 is opened and the electromagnetic valve 40 is closed. Then, the compressor 2 and each of the blowers 15 and 27 are operated, and the air mix damper 28 is blown out from the indoor blower 27 and passes through the heat absorber 9 as shown by a broken line in FIG. It is assumed that air is passed through the auxiliary heater 23 and the radiator 4. As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the electromagnetic valve 30. Since the air in the air flow passage 3 is passed through the radiator 4, the air in the air flow passage 3 is heated by the high-temperature refrigerant in the radiator 4, while the refrigerant in the radiator 4 heats the air. It is deprived and cooled, and condensates.

  The refrigerant that has exited the radiator 4 reaches the outdoor expansion valve 6 through the refrigerant pipe 13E, and flows into the outdoor heat exchanger 7 through the outdoor expansion valve 6 that is controlled to open. The refrigerant flowing into the outdoor heat exchanger 7 is cooled and condensed by running there or by the outside air ventilated by the outdoor blower 15. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 </ b> A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.

  The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 </ b> B, reaches the indoor expansion valve 8 through the internal heat exchanger 19. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. Since the moisture in the air blown out from the indoor blower 27 by the heat absorption action at this time condenses and adheres to the heat absorber 9, the air is cooled and dehumidified.

  The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 through the refrigerant pipe 13C, and repeats circulation that is separated into gas and liquid and sucked into the compressor 2 as described above. In this dehumidifying and cooling mode, since the controller 32 does not energize the auxiliary heater 23, the air cooled by the heat absorber 9 is reheated (reheated in the process of passing through the radiator 4). ) As a result, dehumidifying and cooling in the passenger compartment is performed.

  The controller 32 controls the rotational speed of the compressor 2 based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48, and also uses the outdoor expansion valve based on the high pressure of the refrigerant circuit R described above. 6 is controlled to control the refrigerant pressure of the radiator 4 (radiator pressure PCI).

(4) Cooling Mode Next, in the cooling mode, the controller 32 fully opens the valve opening degree of the outdoor expansion valve 6 in the dehumidifying and cooling mode. The controller 32 controls the air mix damper 28, and the air in the air flow passage 3 after being blown out from the indoor blower 27 and passing through the heat absorber 9 as shown by a solid line in FIG. The rate of ventilation through the vessel 4 is adjusted. Further, the controller 32 does not energize the auxiliary heater 23.

  As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the electromagnetic valve 30, and the refrigerant exiting the radiator 4 passes through the refrigerant pipe 13E and the outdoor expansion valve 6. To. At this time, since the outdoor expansion valve 6 is fully opened, the refrigerant passes through it and flows into the outdoor heat exchanger 7 as it is, where it is cooled by air or by outside air that is ventilated by the outdoor blower 15 and condensed. Liquefaction. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 </ b> A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.

  The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 </ b> B, reaches the indoor expansion valve 8 through the internal heat exchanger 19. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 by the heat absorption action at this time is cooled. Further, moisture in the air condenses and adheres to the heat absorber 9.

  The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 via the refrigerant pipe 13C, and after being gas-liquid separated as described above, the circulation sucked into the compressor 2 is repeated. Since the air cooled and dehumidified by the heat absorber 9 is blown into the vehicle interior from the air outlet 29 (partly passes through the radiator 4 to exchange heat), the vehicle interior is thereby cooled. become. In this cooling mode, the controller 32 rotates the compressor 2 based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO that is the target value. To control.

(5) MAX cooling mode (maximum cooling mode)
Next, in the MAX cooling mode as the maximum cooling mode, the controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21. Further, the electromagnetic valve 30 is closed, the electromagnetic valve 40 is opened, and the valve opening degree of the outdoor expansion valve 6 is fully closed. Then, the compressor 2 and the blowers 15 and 27 are operated, and the air mix damper 28 keeps the air in the air flow passage 3 from passing through the auxiliary heater 23 and the radiator 4 as shown in FIG. However, there is no problem even if it is ventilated somewhat. Further, the controller 32 does not energize the auxiliary heater 23.

  Accordingly, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 to the refrigerant pipe 13G flows into the bypass pipe 35 without going to the radiator 4, passes through the electromagnetic valve 40, and is connected to the refrigerant pipe on the downstream side of the outdoor expansion valve 6. 13E. At this time, since the outdoor expansion valve 6 is fully closed, the refrigerant flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is cooled and condensed by running there or by the outside air ventilated by the outdoor blower 15. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 </ b> A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.

  The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 </ b> B, reaches the indoor expansion valve 8 through the internal heat exchanger 19. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 by the heat absorption action at this time is cooled. In addition, since moisture in the air condenses and adheres to the heat absorber 9, the air in the air flow passage 3 is dehumidified. The refrigerant evaporated in the heat absorber 9 reaches the accumulator 12 through the refrigerant pipe 13C through the internal heat exchanger 19, and repeats circulation that is sucked into the compressor 2 there through. At this time, since the outdoor expansion valve 6 is fully closed, similarly, it is possible to suppress or prevent the disadvantage that the refrigerant discharged from the compressor 2 flows backward from the outdoor expansion valve 6 into the radiator 4. . Thereby, the fall of a refrigerant | coolant circulation amount can be suppressed or eliminated and air-conditioning capability can be ensured now.

  Here, since the high-temperature refrigerant flows through the radiator 4 in the cooling mode described above, direct heat conduction from the radiator 4 to the HVAC unit 10 occurs not a little, but in this MAX cooling mode, the refrigerant flows into the radiator 4. Therefore, the air in the air flow passage 3 from the heat absorber 9 is not heated by the heat transmitted from the radiator 4 to the HVAC unit 10. Therefore, powerful cooling of the passenger compartment is performed, and particularly in an environment where the outside air temperature Tam is high, the passenger compartment can be quickly cooled to realize comfortable air conditioning in the passenger compartment. Also in this MAX cooling mode, the controller 32 rotates the compressor 2 based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO that is the target value. Control the number.

(6) Switching of each operation mode The air flowing through the air flow passage 3 is cooled from the heat absorber 9 and heated from the radiator 4 (and the auxiliary heater 23) in each operation mode (by the air mix damper 28). In response, the air is blown out from the air outlet 29 into the passenger compartment. The controller 32 is set by the air-conditioning operation unit 53, the outside air temperature Tam detected by the outside air temperature sensor 33, the temperature in the vehicle interior detected by the inside air temperature sensor 37, the blower voltage, the amount of solar radiation detected by the solar radiation sensor 51, and the like. The target blowout temperature TAO is calculated based on the target passenger compartment temperature (set temperature) in the passenger compartment, and the temperature of the air blown from the blowout port 29 is controlled to this target blowout temperature TAO by switching each operation mode.

  In this case, the controller 32 determines whether the outside air temperature Tam, the humidity in the vehicle interior, the target outlet temperature TAO, the radiator temperature TH, the target radiator temperature TCO, the heat absorber temperature Te, the target heat absorber temperature TEO, or the dehumidification request in the vehicle interior. By switching each operation mode based on parameters such as, etc., it switches between heating mode, dehumidifying heating mode, dehumidifying cooling mode, cooling mode and MAX cooling mode accurately according to the environmental conditions and necessity of dehumidification. In addition, efficient cabin air conditioning is realized.

(7) Determination 1 of refrigerant leakage by the controller 32 in the heating mode
Next, refrigerant leakage determination control from the refrigerant circuit R by the controller 32 will be described with reference to FIGS. In particular, in the vehicle air conditioner 1 that is used in an environment with much vibration as compared with a normal air conditioner, there is a problem that the refrigerant gradually leaks from the refrigerant circuit R over time. When the refrigerant charge amount in the refrigerant circuit R is reduced, the compressor 2 is seriously damaged. Therefore, it is extremely important for the protection of the device to determine the occurrence of refrigerant leakage at an early stage.

  Here, in the heating mode, since the refrigerant discharged from the outdoor heat exchanger 7 is stored in the accumulator 12, the temperature of the liquid refrigerant in the accumulator 12 is the outdoor heat exchanger temperature TXO. Further, as described above, since the oil must be returned from the accumulator 12 to the compressor 2, the refrigerant discharged from the accumulator 12 includes a part of the liquid refrigerant together with the oil.

  Therefore, when sufficient liquid refrigerant is stored in the accumulator 12, more liquid refrigerant exits from the accumulator 12 through the outlet pipe 61, but the liquid refrigerant output from the accumulator 12 reaches the compressor 2. Evaporates by absorbing heat from the surroundings. And temperature falls under the influence of pressure loss with saturation temperature.

  The state of the refrigerant sucked into the compressor 2 from the accumulator 12 will be described with reference to FIGS. 5 and 6. FIG. 5 is a Ph diagram of the refrigerant circuit R when the evaporation temperature of the refrigerant in the outdoor heat exchanger 7 is 0 ° C., and FIG. 6 is when the evaporation temperature is −10 ° C. Moreover, in each figure, the line shown by L1 is a case where the refrigerant | coolant filling amount in the refrigerant circuit R is enough, and the line shown by L2 is a case where the refrigerant | coolant filling amount is insufficient. L3 is a saturated vapor line.

  As is apparent from this figure, when the refrigerant charging amount is sufficient, the temperature of the refrigerant in the accumulator 2 is the outdoor heat exchanger temperature TXO (0 ° C.), and the time when the refrigerant leaves the accumulator 12 (in FIGS. 5 and 6). In this case, the temperature decreases substantially along the saturated vapor line L3 in the process from the time when it is sucked into the compressor 2 (indicated by Ts in FIGS. 5 and 6). Therefore, in the case of FIG. 5, the difference TXO−Ts between the outdoor heat exchanger temperature TXO and the suction refrigerant temperature Ts is about 17K (TXO = 0 ° C., Ts = −17 ° C.). In the case of FIG. 6, the difference TXO−Ts is It becomes about 10K (TXO = −5 ° C., Ts = −15 ° C.).

  On the other hand, if the refrigerant gradually leaks from the refrigerant circuit R and the refrigerant charging amount becomes insufficient, the amount of liquid refrigerant stored in the accumulator 12 also decreases, so that the liquid refrigerant exiting the accumulator 12 Less, or almost never go out. Therefore, the temperature of the refrigerant sucked into the compressor 2 (suction refrigerant temperature Ts) increases due to the influence of heat from the surroundings.

  This state is indicated by L2 in FIGS. In the case of FIG. 5, the suction refrigerant temperature Ts is about −5 ° C., and in the case of FIG. Therefore, in the case of FIG. 5, the difference TXO−Ts between the outdoor heat exchanger temperature TXO and the suction refrigerant temperature Ts is about 5K (TXO = 0 ° C., Ts = −5 ° C.). In FIG. 6, the difference TXO−Ts is It becomes about 0K (TXO = −5 ° C., Ts = −5 ° C.).

  That is, it can be seen that there is a correlation between the difference TXO-Ts between the outdoor heat exchanger temperature TXO and the suction refrigerant temperature Ts and the refrigerant charge amount in the refrigerant circuit R. FIG. 7 shows the results of measuring this correlation. It can be seen that the difference TXO-Ts decreases as the refrigerant charge amount decreases. If the minimum refrigerant charging amount allowed in the refrigerant circuit R is, for example, 550 g, it can be seen that the refrigerant must be replenished when the difference TXO-Ts is reduced to 5K.

  Therefore, the controller 32 determines the difference TXO−Ts based on the difference TXO−Ts between the outdoor heat exchanger temperature TXO detected by the outdoor heat exchanger temperature sensor 54 and the suction refrigerant temperature Ts of the compressor 2 detected by the suction temperature sensor 55. When -Ts becomes smaller than 5K (predetermined value), it is determined that refrigerant leakage has occurred. Then, the occurrence of refrigerant leakage is displayed by the air conditioning operation unit 53 and notified to the user (notification operation).

  In other words, in the embodiment, the amount of liquid refrigerant in the accumulator 12 is detected based on a change in the difference TXO-Ts between the outdoor heat exchanger temperature TXO and the suction refrigerant temperature Ts. And generation | occurrence | production of a refrigerant | coolant leakage is determined based on the quantity of this liquid refrigerant. As a result, even when the refrigerant gradually leaks from the refrigerant circuit R, it is determined that the refrigerant has leaked at an early stage, thereby avoiding inconvenience that the compressor 2 is seriously damaged. Will be able to.

  When the controller 32 determines that the refrigerant leakage has occurred, the air conditioning operation unit 53 performs a notification operation, so that the user is warned of the occurrence of the refrigerant leakage and prompts the user to take quick measures such as refrigerant replenishment. Will be able to.

  In particular, in the embodiment, based on the difference TXO-Ts between the outdoor heat exchanger temperature TXO and the suction refrigerant temperature Ts of the compressor 2, when this difference TXO-Ts becomes smaller than a predetermined value, refrigerant leakage occurs. Therefore, it is possible to accurately determine the occurrence of refrigerant leakage. In addition, since the refrigerant leakage determination can be performed by using the outdoor heat exchanger temperature sensor 54 and the suction temperature sensor 55 together, it is necessary to provide a plurality of temperature sensors for directly detecting the amount of liquid refrigerant in the accumulator 12. As a result, the number of parts can be reduced.

(8) Refrigerant leakage determination 2 by the controller 32 in the heating mode 2
Here, the difference TXO−Ts between the outdoor heat exchanger temperature TXO and the suction refrigerant temperature Ts is also correlated with the superheat degree SH of the refrigerant sucked into the compressor 2. This is shown in FIG. When the amount of liquid refrigerant in the accumulator 12 is sufficient, the difference TXO-Ts increases as described above, and the superheat degree SH of the refrigerant sucked into the compressor 2 decreases. On the other hand, when the amount of the liquid refrigerant in the accumulator 12 is insufficient, the difference TXO-Ts is reduced as described above, and the superheat degree SH of the refrigerant sucked into the compressor 2 is increased.

  That is, the greater the difference TXO-Ts, the smaller the superheat degree SH, and the smaller the difference TXO-Ts, the greater the superheat degree SH. The superheat degree SH when the above-described difference TXO-Ts is 5K is about 7K. Therefore, the superheat degree SH (obtained from the pressure and temperature of the suction refrigerant detected by the suction pressure sensor 44 and the suction temperature sensor 55) of the refrigerant sucked into the compressor 2 by the controller 32 is larger than 5K (predetermined value). In such a case, it may be determined that refrigerant leakage has occurred. The occurrence of refrigerant leakage can be accurately determined by the superheat degree SH of the refrigerant sucked into the compressor 2 as described above. Similarly, it is not necessary to provide a plurality of temperature sensors that directly detect the amount of liquid refrigerant in the accumulator 12.

  In each of the above embodiments, the amount of liquid refrigerant in the accumulator 12 is detected based on the difference TXO-Ts between the outdoor heat exchanger temperature TXO and the suction refrigerant temperature Ts and the degree of superheat SH of the refrigerant sucked into the compressor 2. Although the occurrence of refrigerant leakage has been determined, the invention of claim 1 is not limited to this, and a plurality of temperature sensors are attached to the accumulator 12 to detect the amount of liquid refrigerant stored therein, and the amount of liquid refrigerant is directly determined. You may make it determine.

  In the embodiment, the present invention has been described with an example in which each operation mode of the heating mode, the dehumidifying heating mode, the dehumidifying cooling mode, the cooling mode, and the MAX cooling mode is switched. However, the present invention is not limited thereto, and the vehicle air that executes only the heating mode. The present invention is also effective for a harmony device.

  Furthermore, the switching control of each operation mode shown in the embodiment is not limited thereto, and the outside air temperature Tam, the humidity in the passenger compartment, the target outlet temperature TAO, depending on the capability and usage environment of the vehicle air conditioner, Adopt any one of parameters such as radiator temperature TH, target radiator temperature TCO, heat absorber temperature Te, target heat absorber temperature TEO, presence / absence of dehumidification request in vehicle interior, or a combination thereof, or all of them. Appropriate conditions should be set.

  Furthermore, the auxiliary heating device is not limited to the auxiliary heater 23 shown in the embodiment, and a heat medium circulation circuit that heats the air in the air flow passage by circulating the heat medium heated by the heater or an engine. You may utilize the heater core etc. which circulate through the heated radiator water. Moreover, the structure of the refrigerant circuit R demonstrated in the Example is not limited to it, It can change in the range which does not deviate from the meaning of this invention.

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 2 Compressor 3 Air flow path 4 Radiator 6 Outdoor expansion valve 7 Outdoor heat exchanger 8 Indoor expansion valve 9 Heat absorber 17, 21, 30, 40 Electromagnetic valve 23 Auxiliary heater (auxiliary heating device)
27 Indoor blower
28 Air Mix Damper 32 Controller (Control Device)
35 Bypass piping 44 Suction pressure sensor 54 Outdoor heat exchanger temperature sensor 55 Suction temperature sensor R Refrigerant circuit

Claims (4)

A compressor for compressing the refrigerant;
An air flow passage through which air to be supplied into the passenger compartment flows;
A radiator for radiating the refrigerant to heat the air supplied from the air flow passage to the vehicle interior;
An outdoor heat exchanger provided outside the vehicle compartment;
An accumulator connected to the refrigerant suction side of the compressor;
A control device,
At least the refrigerant discharged from the compressor is radiated by the radiator by the control device, and the radiated refrigerant is decompressed and then absorbed by the outdoor heat exchanger to heat the vehicle interior. In the air conditioner,
The vehicle air conditioner characterized in that the control device detects the amount of liquid refrigerant in the accumulator and determines the occurrence of refrigerant leakage based on the amount of liquid refrigerant.   When the difference TXO-Ts becomes smaller than a predetermined value based on the difference TXO-Ts between the temperature TXO of the outdoor heat exchanger and the suction refrigerant temperature Ts of the compressor, refrigerant leakage occurs. The vehicle air conditioner according to claim 1, wherein the air conditioner for a vehicle is determined.   2. The control device according to claim 1, wherein the controller determines that refrigerant leakage has occurred when the superheat degree SH is greater than a predetermined value based on the superheat degree SH of the refrigerant sucked into the compressor. The vehicle air conditioning apparatus described.   The vehicle air conditioner according to any one of claims 1 to 3, wherein the control device performs a predetermined notification operation when it is determined that the refrigerant leakage has occurred. .

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