CN110049887B - Air conditioner for vehicle - Google Patents

Abstract

Provided is a vehicle air conditioner which can efficiently remove the fog of a front window when a DEF blowing mode is selected. A vehicle air-conditioning device (1) is provided with a compressor (2), an air flow path (3), a radiator (4), a heat absorber (9), and an outdoor heat exchanger (7). The controller has a DEF blowing mode for blowing air supplied into the vehicle interior at least to the inside of a front window (50) of the vehicle, and when the DEF blowing mode is selected, executes a heating mode in which the refrigerant discharged from the compressor (2) is released heat by the radiator (4), the pressure of the refrigerant after the heat release is reduced, and the refrigerant absorbs heat by the outdoor heat exchanger (7).

Description

Air conditioner for vehicle

Technical Field

The present invention relates to a heat pump type vehicle air conditioning apparatus for conditioning air in a vehicle interior.

Background

Due to recent environmental problems, hybrid vehicles and electric vehicles have become widespread. As an air conditioning apparatus applicable to such a vehicle, the following apparatus has been developed: the air conditioner includes a compressor for compressing and discharging a refrigerant, a radiator for radiating heat from the refrigerant disposed inside a vehicle interior, a heat absorber for absorbing heat from the refrigerant disposed inside the vehicle interior, and an exterior heat exchanger for radiating or absorbing heat from the refrigerant disposed outside the vehicle interior, and is switchable between a heating mode in which the refrigerant discharged from the compressor radiates heat at the radiator to absorb heat at the exterior heat exchanger, a dehumidifying heating mode in which the refrigerant discharged from the compressor radiates heat at the radiator to absorb heat at the heat absorber and the exterior heat exchanger, a dehumidifying cooling mode in which the refrigerant discharged from the compressor radiates heat at the radiator and the exterior heat exchanger to absorb heat at the heat absorber, and a cooling mode in which the refrigerant discharged from the compressor radiates heat at the exterior heat exchanger to absorb heat at the heat absorber (for example, see patent document 1).

Patent document 1: japanese patent laid-open No. 2014-213765.

Patent document 2: japanese patent laid-open publication No. 2014-8858.

In the dehumidification heating mode described above, the vehicle interior is heated and dehumidified, thereby removing fog from the windows (front windows, etc.) of the vehicle at low outside temperatures such as in winter. Further, there is also a method in which an auxiliary heating mechanism as in patent document 1 is provided, and in the dehumidification heating mode, air blown into the vehicle interior is heated by the auxiliary heating mechanism, and the refrigerant absorbs heat by the heat absorber to dehumidify the air.

On the other hand, each of the outlets, which are formed in the vehicle interior, such as the FOOT (FOOT section: air blowing toward the FOOT), the VENT (air blowing toward the chest of the occupant), and the DEF (defrosting: air blowing toward the inside of the front window), can be selected in the automatic mode or in the manual operation of the button, among the VENT outlet air blowing mode, the B/L outlet air blowing mode, both the VENT and the VENT, and the DEF outlet air blowing mode, when the DEF outlet mode is selected, the front window can be cleared of fog if the temperature of the front window (the temperature on the inside) can be made equal to or higher than the dew point temperature of the vehicle interior air by the blown air.

Disclosure of Invention

The present invention has been made to solve the conventional problems, and an object of the present invention is to provide a vehicle air-conditioning apparatus capable of efficiently removing the fog of the front window when the DEF blowing mode is selected.

The vehicle air conditioner of the present invention includes a compressor for compressing a refrigerant, an air flow passage through which air supplied into a vehicle interior flows, a radiator for radiating heat from the refrigerant to heat the air supplied from the air flow passage into the vehicle interior, a heat absorber for absorbing heat from the refrigerant to cool the air supplied from the air flow passage into the vehicle interior, and a controller for executing a DEF blowing mode in which the air supplied into the vehicle interior is blown out at least to the inside of a front window of the vehicle by the radiator, and when the DEF blowing mode is selected, the controller executes a heating mode in which the refrigerant discharged from the compressor is radiated by the radiator to decompress the refrigerant after the heat is radiated, it absorbs heat by means of an outdoor heat exchanger.

In the vehicle air-conditioning apparatus according to the invention of claim 2, in the above-described invention, the controller controls the operation of the compressor in the warm air mode based on the target outlet temperature TAO that is a target value of the temperature of the air blown into the vehicle interior or a value derived from the target outlet temperature TAO, and has a plurality of outlet modes including the DEF outlet mode.

The vehicle air-conditioning apparatus according to the invention recited in claim 3 is configured such that, in each of the above-described inventions, the vehicle air-conditioning apparatus includes a flow path switching device for switching a flow path of the refrigerant, and the control device controls the flow path switching device to switch between a plurality of operation modes including a heating mode and to switch to the heating mode when the DEF blowing mode is selected in a state of operation in an operation mode other than the heating mode.

In the vehicle air-conditioning apparatus according to the invention of claim 4, in the above invention, the controller fixes the operation mode to the heating mode in the DEF blowing mode.

In the vehicle air-conditioning apparatus according to the invention of claim 5, in the invention of claim 3 or claim 4, the control device has, as the operation mode, a dehumidification heating mode in which the refrigerant discharged from the compressor is radiated by the radiator, the refrigerant after radiation is decompressed and then absorbed by the heat absorber and the outdoor heat exchanger, and when the DEF blowing mode is selected while the vehicle air-conditioning apparatus is operating in the dehumidification heating mode, the operation mode is switched to the heating mode.

The vehicle air-conditioning apparatus according to the invention of claim 6 is the vehicle air-conditioning apparatus according to the invention of claim 3 or claim 4, which includes an auxiliary heating device for heating air supplied from the air flow passage into the vehicle interior, and the control device has a dehumidification heating mode as an operation mode, in which the refrigerant discharged from the compressor is caused to flow to the outdoor heat exchanger without flowing to the radiator to release heat, the refrigerant after the heat release is decompressed, the refrigerant is caused to absorb heat by the heat absorber, the auxiliary heating device is caused to generate heat, and the operation mode is switched to the heating mode when the DEF blowing mode is selected.

Effects of the invention

According to the present invention, in a vehicle air-conditioning apparatus including a compressor that compresses a refrigerant, an air flow passage through which air supplied into a vehicle interior circulates, a radiator that radiates heat from the refrigerant to heat air supplied from the air flow passage into the vehicle interior, a heat absorber that absorbs heat from the refrigerant to cool the air supplied from the air flow passage into the vehicle interior, an outdoor heat exchanger that is provided outside the vehicle interior, and a controller that executes a heating mode in which the refrigerant discharged from the compressor is radiated by the radiator, the refrigerant after radiation is decompressed by the outdoor heat exchanger to absorb heat by a DEF blowing mode in which the air supplied into the vehicle interior is blown out at least to the inside of a front window of the vehicle, therefore, the temperature of the air in the vehicle interior inside the front window can be quickly and effectively set to the dew point temperature or higher to eliminate the fog in the front window.

In this case, since dehumidification by the heat absorber is not performed as in the dehumidification-air heating mode of the inventions of claims 5 and 6, a problem of deterioration in operation efficiency is avoided, mist of the front window can be efficiently eliminated, and power consumption in the DEF blowing mode can be reduced.

Further, the control device as in the invention of claim 2 controls the operation of the compressor on the basis of the target air-blowing temperature TAO, which is the target value of the temperature of the air blown into the vehicle interior in the warm air mode, or a value derived from the target air-blowing temperature TAO, and has a plurality of air-blowing modes including the DEF air-blowing mode, and when the DEF air-blowing mode is selected, the target air-blowing temperature TAO is increased as compared with when another air-blowing mode is selected, the air is heated by the radiator in the warm air mode, the temperature of the air blown out toward the inside of the front window in the DEF air-blowing mode is increased, and the fog of the front window can be quickly eliminated.

In this vehicle air conditioning apparatus, the control device switches between a plurality of operation modes including a heating mode by controlling the flow path switching device for switching the flow path of the refrigerant, but in this case, when the control device as in the invention of claim 3 selects the DEF blowing mode in a state of operating in an operation mode other than the heating mode, switching to the heating mode enables efficient defogging of the front window as compared with other operation modes such as the dehumidification and heating mode of the inventions of claim 5 and claim 6.

In this case, the controller according to the invention of claim 4 fixes the operation mode to the warm air mode in the DEF air blowing mode, and thereby can avoid a problem that the operation mode is switched to an operation mode other than the warm air mode even in a state where the DEF air blowing mode is assumed.

Drawings

Fig. 1 is a configuration diagram of a vehicle air-conditioning apparatus to which an embodiment of the present invention is applied (example 1).

Fig. 2 is a block diagram of an electrical circuit of a controller of the vehicle air-conditioning apparatus of fig. 1.

Fig. 3 is a control block diagram of compressor control with respect to the controller of fig. 2.

Fig. 4 is a control block diagram for control of the outdoor expansion valve of the controller of fig. 2.

Fig. 5 is a configuration diagram of a vehicle air-conditioning apparatus to which another embodiment of the present invention is applied (example 2).

Detailed Description

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

Example 1

Fig. 1 is a block diagram of a vehicle air-conditioning apparatus 1 to which an embodiment of the present invention is applied. A vehicle to which an embodiment of the present invention is applied is an Electric Vehicle (EV) not equipped with an engine (internal combustion engine), and travels by driving an electric motor for traveling with electric power charged in a battery (both not shown), and the vehicle air-conditioning apparatus 1 of the present invention is also driven with electric power of the battery. That is, in the vehicle air-conditioning apparatus 1 according to the embodiment, in the electric vehicle in which the warm air generated by the engine waste heat cannot be generated, the warm air mode is performed by operating the heat pump using the refrigerant circuit, and the operation modes of the dehumidification warm air mode, the internal circulation mode, the dehumidification cool air mode, the cool air mode, and the auxiliary heater individual mode are selectively switched and executed.

The present invention is also effective not only for electric vehicles but also for so-called hybrid vehicles using both an engine and an electric motor for traveling, and is also applicable to ordinary vehicles traveling by an engine.

The vehicle air-conditioning apparatus 1 of the embodiment performs air conditioning (heating, cooling, dehumidification, and ventilation) of the vehicle interior of an electric vehicle, and a refrigerant circuit R is configured by sequentially connecting a compressor 2, a radiator 4, an outdoor expansion valve (pressure reducing device) 6, an outdoor heat exchanger 7, an indoor expansion valve (pressure reducing device) 8, a heat absorber 9, an accumulator 12, and the like via a refrigerant pipe 13, the compressor 2 compresses a refrigerant, the radiator 4 is electrically operated, the radiator 4 is provided in an air flow passage 3 of an HVAC unit 10 through which air in the vehicle interior is ventilated and circulated, a high-temperature and high-pressure refrigerant discharged from the compressor 2 flows in via a refrigerant pipe 13G to release the refrigerant into the vehicle interior, the outdoor expansion valve (pressure reducing device) 6 is configured by an electrically operated valve which decompresses and expands the refrigerant at the time of heating, and the outdoor heat exchanger 7 functions as a radiator at the time of cooling, the indoor expansion valve (decompression device) 8 is constituted by an electrically operated valve for decompressing and expanding the refrigerant, and the heat absorber 9 is provided in the air flow path 3 for absorbing heat from the inside and outside of the vehicle compartment during cooling and dehumidification.

Further, an outdoor fan 15 is provided in the outdoor heat exchanger 7. The outdoor fan 15 is configured to forcibly ventilate the outdoor air to the outdoor heat exchanger 7 to exchange heat between the outdoor air and the refrigerant, and thereby ventilate the outdoor air to the outdoor heat exchanger 7 even when the vehicle is stopped (i.e., the vehicle speed is 0 km/h).

The exterior heat exchanger 7 includes a receiver/dryer 14 and a subcooling unit 16 in this order on the downstream side of the refrigerant, and a refrigerant pipe 13A connected to the refrigerant outlet of the exterior heat exchanger 7 is connected to the receiver/dryer 14 via an open solenoid valve 17 during cooling, and the outlet of the subcooling unit 16 is connected to the indoor expansion valve 8 via a check valve 18. The receiver drier 14 and the subcooling unit 16 structurally constitute a part of the outdoor heat exchanger 7, and the check valve 18 is disposed on the side of the indoor expansion valve 8 in the forward direction.

The refrigerant pipe 13B between the check valve 18 and the indoor expansion valve 8 is provided in a heat exchange relationship with the refrigerant pipe 13C located on the outlet side of the heat absorber 9, and the two pipes constitute an internal heat exchanger 19. Thereby, the refrigerant flowing into the indoor expansion valve 8 through the refrigerant pipe 13B is cooled (supercooled) by the low-temperature refrigerant coming out of the heat absorber 9.

The refrigerant pipe 13A branches off from the exterior heat exchanger 7, and the branched refrigerant pipe 13D is connected to the refrigerant pipe 13C on the downstream side of the interior heat exchanger 19 via an electromagnetic valve 21 opened during heating. The refrigerant pipe 13C is connected to the accumulator 12, and the accumulator 12 is connected to the refrigerant suction side of the compressor 2. Further, an evaporation pressure adjusting valve 11 is connected to the refrigerant pipe 13C on the outlet side of the heat absorber 9 and on the refrigerant downstream side of the internal heat exchanger 19, on the refrigerant upstream side of the merging point with the refrigerant pipe 13D.

Further, the refrigerant pipe 13E on the outlet side of the radiator 4 branches into a refrigerant pipe 13J and a refrigerant pipe 13F in front of the outdoor expansion valve 6, and the branched refrigerant pipe 13J is connected to the refrigerant inlet of the exterior heat exchanger 7 via the outdoor expansion valve 6. The other branched refrigerant pipe 13F is connected to the refrigerant pipe 13B on the downstream side of the check valve 18 via an electromagnetic valve 22 that is opened during dehumidification. Thereby, the refrigerant pipe 13F becomes a bypass circuit connected in parallel to the series circuit of the outdoor expansion valve 6 and the outdoor heat exchanger 7. The solenoid valve 22 is connected to a middle portion of the bypass circuit (refrigerant pipe 13F). These solenoid valves 17, 21, and 22 constitute a flow path switching device according to the present invention.

Further, in the air flow passage 3 on the air upstream side of the heat absorber 9, there are formed an outside air suction port and an inside air suction port (representatively shown by a suction port 25 in fig. 1), and a suction switching damper 26 is provided in the suction port 25, and the suction switching damper 26 switches the air introduced into the air flow passage 3 to inside air, which is air in the vehicle interior (inside air circulation mode), and outside air, which is air outside the vehicle interior (outside air introduction mode). Further, an indoor blower (blower) 27 for feeding the introduced indoor air and outdoor air to the airflow passage 3 is provided on the air downstream side of the intake switching damper 26.

In fig. 1, reference numeral 23 denotes an auxiliary heater as an auxiliary heating device provided in the vehicle air-conditioning apparatus 1 according to the embodiment. The auxiliary heater 23 is constituted by a PTC heater (electric heater) in the embodiment, and is provided in the air flow passage 3 on the downstream side of the air as the radiator 4 with respect to the flow of the air in the air flow passage 3 in the embodiment. When the auxiliary heater 23 (auxiliary heating device) is energized to generate heat (operate), it is a so-called heater core that supplements warm air in the vehicle interior. In this way, if the auxiliary heater 23 is disposed downstream of the radiator 4 with respect to the flow of the air in the air flow path 3, the problem that the radiator 4 absorbs heat from the air warmed by the auxiliary heater 23 is solved. This can prevent deterioration in the operation efficiency of the vehicle air-conditioning apparatus 1.

Here, the air flow passage 3 on the leeward side (air downstream side) of the heat absorber 9 of the HVAC unit 10 is divided by a partition wall 10A to form a heating heat exchange passage 3A and a bypass passage 3B bypassing the heating heat exchange passage 3A, and the radiator 4 and the auxiliary heater 23 are disposed in the heating heat exchange passage 3A. An air mix damper 28 is provided in the air flow path 3 on the air upstream side of the radiator 4, and the air mix damper 28 adjusts the ratio of ventilation of the air (inside air, outside air) in the air flow path 3 flowing into the air flow path 3 and passing through the heat absorber 9 to the radiator 4 and the auxiliary heater 23 in the heating heat exchange path 3A.

Further, in the HVAC unit 10 on the leeward side of the radiator 4 and the auxiliary heater 23, respective blow outlets of the FOOT (FOOT) blow outlets 29A, VENT (vent) blow outlets 29B, DEF (defroster) blow outlets 29C are formed. The FOOT outlet 29A is an outlet for blowing air toward the underfoot of the vehicle interior. The VENT outlet 29B is an outlet for blowing air toward the chest and the face of the occupant in the vehicle interior. The DEF outlet 29C is an outlet for blowing air into the front glass 70 and the side windows (at least the front window 70) of the vehicle. The hot outlet port 29A, VENT and the DEF outlet port 29B and 29C are provided with respective outlet port dampers of a hot outlet port damper 31A, VENT and a DEF outlet port damper 31C that control the amount of air blown out.

The controller 32, which will be described later, is configured to have a FOOT air-blowing mode in which air is blown out from the FOOT air outlet 29A, a VENT air-blowing mode in which air is blown out from the VENT air outlet 29B, a B/L air-blowing mode in which air is blown out from both the VENT air outlet 29B and the FOOT air outlet 29A, and a DEF air-blowing mode in which air is blown out from the DEF air outlet 29C, and each air-blowing mode is selected in an automatic mode or based on a manual operation of an air conditioning operation unit 53, which will be described later. In particular, when the DEF button 53A provided in the air conditioning operation unit 53 is turned on by the occupant, the controller 32 is configured to switch the air blowing mode to the DEF air blowing mode and increase the air volume (mass air volume Ga of air, which will be described later) of the indoor fan 27.

Next, 32 in fig. 2 is a controller (ECU) as a control device. The control isThe device 32 (control device) is constituted by a microcomputer as an example of a computer provided with a processor, to which an outside air temperature sensor 33, an outside air humidity sensor 34, an HVAC intake temperature sensor 36, an inside air temperature sensor 37, an inside air humidity sensor 38, and an indoor CO are connected as input ₂ Outputs of a concentration sensor 39, a blowout temperature sensor 41, a discharge pressure sensor 42, a discharge temperature sensor 43, a suction pressure sensor 44, a radiator temperature sensor 46, a radiator pressure sensor 47, a heat absorber temperature sensor 48, a heat absorber pressure sensor 49, a insolation sensor 51, a vehicle speed sensor 52, an air conditioning (air conditioning) operation unit 53, an outdoor heat exchanger temperature sensor 54, and an outdoor heat exchanger pressure sensor 56, the outside air temperature sensor 33 detects an outside air temperature (Tam) of the vehicle, the outside air humidity sensor 34 detects an outside air humidity, the HVAC suction temperature sensor 36 detects a temperature of air sucked from the suction port 25 to the air flow path 3, the inside air temperature sensor 37 detects a temperature of air (inside air) in the vehicle interior, the inside air humidity sensor 38 detects a humidity of air in the vehicle interior, aforesaid indoor CO ₂ A concentration sensor 39 detects the concentration of carbon dioxide in the vehicle interior, a blowout temperature sensor 41 detects the temperature of air blown into the vehicle interior (blowout temperature TAI), a discharge pressure sensor 42 detects the pressure of refrigerant discharged from the compressor 2 (discharge pressure Pd), a discharge temperature sensor 43 detects the temperature of refrigerant discharged from the compressor 2, a suction pressure sensor 44 detects the pressure of refrigerant sucked into the compressor 2, a radiator temperature sensor 46 detects the temperature of the radiator 4 (the temperature of air passing through the radiator 4 or the temperature of the radiator 4 itself: radiator temperature TCI), a radiator pressure sensor 47 detects the pressure of refrigerant in the radiator 4 (the pressure of refrigerant in the radiator 4 or immediately after the radiator 4: radiator pressure PCI), a heat absorber temperature sensor 48 detects the temperature of the heat absorber 9 (the temperature of air passing through the heat absorber 9 or the temperature of the heat absorber 9 itself: heat absorber temperature Te), the absorber pressure sensor 49 detects the refrigerant pressure of the absorber 9 (the pressure of the refrigerant inside the absorber 9 or immediately after the refrigerant exits from the absorber 9), and the insolation sensor 51 detects the amount of insolation in the vehicle interior, for exampleThe vehicle speed sensor 52 is of a photoelectric sensor type, the air conditioning (air conditioning) operation unit 53 is for setting a set temperature and switching an operation mode, the exterior heat exchanger temperature sensor 54 detects a temperature of the exterior heat exchanger 7 (a temperature of the refrigerant immediately after the exterior heat exchanger 7 or a temperature of the exterior heat exchanger 7 itself), and the exterior heat exchanger pressure sensor 56 detects a refrigerant pressure of the exterior heat exchanger 7 (a pressure of the refrigerant in the exterior heat exchanger 7 or immediately after the exterior heat exchanger 7).

In this case, an air-conditioning operation unit 53 is provided with an air-blowing mode selection button including the DEF button 53A, and the DEF air-blowing mode, VENT air-blowing mode, FOOT air-blowing mode, and B/L air-blowing mode are switched by the on operation of each button, but only the DEF button 53A is illustrated in fig. 2. Further, the controller 32 has an input connected to an output of a sub-heater temperature sensor 50 that detects the temperature of the sub-heater 23 (the temperature of the air passing through the sub-heater 23 or the temperature of the sub-heater 23 itself: the sub-heater temperature Tptc).

On the other hand, the output of the controller 32 is connected to the compressor 2, the outdoor fan 15, the indoor fan (fan) 27, the intake switching damper 26, the air mixing damper 28, the outlet dampers 31A to 31C, the outdoor expansion valve 6, the indoor expansion valve 8, the solenoid valves 22 (dehumidification), the solenoid valve 17 (cold air), the solenoid valves 21 (warm air), the evaporation pressure adjusting valve 11, and the auxiliary heater 23. The controller 32 controls the outputs of the sensors based on the settings input from the air conditioning operation unit 53.

In the above configuration, the operation of the vehicle air-conditioning apparatus 1 according to the embodiment will be described next. In this embodiment, the controller 32 switches and executes each operation mode of the warm air mode, the dehumidification warm air mode, the internal circulation mode, the dehumidification cool air mode, the cool air mode, and the auxiliary heater individual mode. First, each operation mode will be described.

(1) Heating mode

When the heating mode is selected by the controller 32 (automatic mode) or by manual operation of the air conditioning operation unit 53 (manual mode), the controller 32 opens the electromagnetic valve 21 (for heating) and closes the electromagnetic valve 17. Further, the electromagnetic valve 22 is closed.

The compressor 2 and the blowers 15 and 27 are operated, and the air mix door 28 is in a state of adjusting the ratio of the air blown out from the indoor blower 27 to be blown to the radiator 4 and the auxiliary heater 23 in the heating heat exchange path 3A. Thereby, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4. Since the air in the air flow path 3 is ventilated to the radiator 4, the air in the air flow path 3 is heated by the high-temperature refrigerant in the radiator 4 (the radiator 4 and the auxiliary heater 23 when the auxiliary heater 23 is operated), while the refrigerant in the radiator 4 is cooled by the air taking heat, and condensed and liquefied.

All the refrigerant liquefied in the radiator 4 is discharged from the radiator 4, and then reaches the outdoor expansion valve 6 through the refrigerant pipes 13E and 13J. The refrigerant flowing into the outdoor expansion valve 6 is decompressed and flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 evaporates to travel or absorb heat from the outside air ventilated by the outdoor fan 15. That is, the refrigerant circuit R becomes a heat pump. The low-temperature refrigerant discharged from the exterior heat exchanger 7 repeats the following cycle: the refrigerant enters the accumulator 12 from the refrigerant pipe 13C through the refrigerant pipe 13A, the solenoid valve 21, and the refrigerant pipe 13D, and after gas-liquid separation, the gas refrigerant is sucked into the compressor 2.

That is, in this heating mode, the refrigerant evaporates only in the exterior heat exchanger 7 to extract heat from the outside air, and the air in the air flow passage 3 is heated by the extracted heat via the radiator 4. The heated air is blown out from the air outlets 29A to 29C through the auxiliary heater 23, and thus, the vehicle interior is warmed.

The controller 32 calculates a target radiator pressure PCO (target value of the radiator pressure PCI) based on a target outlet air temperature TAO described later or a target radiator temperature TCO (target value of the radiator temperature TCI) calculated based on the target outlet air temperature TAO, and controls the rotation speed of the compressor 2 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. The valve opening degree of the outdoor expansion valve 6 is controlled based on the radiator temperature TCI detected by the radiator temperature sensor 46 and the radiator pressure PCI detected by the radiator pressure sensor 47, and the degree of Supercooling (SC) of the refrigerant at the outlet of the radiator 4 is controlled.

In the embodiment, the target radiator pressure PCO is calculated from the target radiator temperature TCO, but the target radiator pressure PCO may be directly calculated from the target blow-out temperature TAO to control the rotation speed of the compressor 2. In the embodiment, the target heat radiator temperature TCO is substantially TCO TAO, but a predetermined limit is set in the control.

(2) Dehumidification heating mode

Next, in the dehumidification warm air mode, the controller 32 opens the electromagnetic valve 22 in the state of the warm air mode. Thereby, a part of the condensed refrigerant flowing through the radiator 4 in the refrigerant pipe 13E is branched, and the part flows into the refrigerant pipe 13F through the solenoid valve 22, flows from the refrigerant pipe 13B to the indoor expansion valve 8 through the internal heat exchanger 19, and the rest flows to the outdoor expansion valve 6. That is, a part of the branched refrigerant is decompressed by the indoor expansion valve 8, flows into the heat exchanger 9, and evaporates.

The controller 32 controls the valve opening degree of the indoor expansion valve 8 so that the superheat degree (SH) of the refrigerant at the outlet of the heat absorber 9 is maintained at a predetermined value, but at this time, the refrigerant is condensed by moisture in the air blown out from the indoor fan 27 due to the heat absorption action of the refrigerant by the heat absorber 9 and adheres to the heat absorber 9, so that the air is cooled and dehumidified. The remaining refrigerant branched and flowing into the refrigerant pipe 13J is decompressed by the outdoor expansion valve 6, evaporated in the outdoor heat exchanger 7, and absorbs heat from the outside air.

The refrigerant evaporated in the heat exchanger 9 repeats the following cycle: the refrigerant passes through the internal heat exchanger 19 and the evaporation pressure adjustment valve 11 in this order, merges with the refrigerant from the refrigerant pipe 13D (the refrigerant from the exterior heat exchanger 7) via the refrigerant pipe 13C, and is then sucked into the compressor 2 via the accumulator 12. The air dehumidified by the heat absorber 9 is reheated while passing through the radiator 4 (the radiator 4 and the auxiliary heater 23 when the auxiliary heater 23 generates heat), and thus, dehumidification and heating of the vehicle interior are performed.

The controller 32 controls the rotation speed of the compressor 2 based on the target radiator pressure PCO calculated from the target radiator temperature TCO and the radiator pressure PCI (high pressure of the refrigerant circuit R) detected by the radiator pressure sensor 47, and controls the valve opening degree of the outdoor expansion valve 6 based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48. The controller 32 opens (amplifies the flow path) and closes (slightly flows the refrigerant) the evaporation pressure adjusting valve 11 based on the temperature Te of the heat absorber 9 detected by the heat absorber temperature sensor 48, thereby preventing the heat absorber 9 from freezing due to an excessive temperature drop.

(3) Internal circulation mode

Next, in the internal circulation mode, the controller 32 fully closes the outdoor expansion valve 6 (fully closed position) and closes the electromagnetic valve 21 in the state of the dehumidification heating mode. That is, since the internal circulation mode is a state in which the outdoor expansion valve 6 is fully closed by the control of the outdoor expansion valve 6 in the dehumidification-air heating mode, the internal circulation mode is a part of the dehumidification-air heating mode in the present invention.

However, since the inflow of the refrigerant into the exterior heat exchanger 7 and the outflow of the refrigerant from the exterior heat exchanger 7 are prevented by closing the exterior expansion valve 6 and the solenoid valve 21, all of the condensed refrigerant flowing through the radiator 4 in the refrigerant pipe 13E flows to the refrigerant pipe 13F through the solenoid valve 22. The refrigerant flowing through the refrigerant pipe 13F passes through the refrigerant pipe 13B and the internal heat exchanger 19, and reaches the indoor expansion valve 8. The refrigerant is decompressed by the indoor expansion valve 8, flows into the heat absorber 9, and evaporates. By the heat absorption action at this time, moisture in the air blown out from the indoor fan 27 condenses and adheres to the heat absorber 9, so the air is cooled and dehumidified.

The refrigerant evaporated by the heat absorber 9 repeats the following cycle: the refrigerant flows through the internal heat exchanger 19 and the evaporation pressure adjustment valve 11 in this order through the refrigerant pipe 13C, passes through the accumulator 12, and is sucked into the compressor 2. The air dehumidified by the heat absorber 9 is reheated while passing through the radiator 4, and thus, dehumidified heating of the vehicle interior is performed, but in this internal circulation mode, the refrigerant is circulated between the radiator 4 (heat radiation) and the heat absorber 9 (heat absorption) in the indoor air flow path 3, and therefore, the heating capacity according to the power consumption of the compressor 2 is exhibited without extracting heat from the outside air. Since all the refrigerant flows to the heat absorber 9 that performs dehumidification, the dehumidification capability is higher but the heating capability is lower than in the dehumidification heating mode.

The controller 32 controls the rotation speed of the compressor 2 based on the temperature of the heat absorber 9 or the radiator pressure PCI (high pressure of the refrigerant circuit R). At this time, the controller 32 selects the lower one of the target compressor rotation speeds obtained by the calculation based on the temperature of the heat absorber 9 or the radiator pressure PCI to control the compressor 2.

(4) Dehumidification cooling air mode

Next, in the dehumidification cooling air mode, the controller 32 opens the solenoid valve 17 and closes the solenoid valve 21. Further, the electromagnetic valve 22 is closed. The compressor 2 and the blowers 15 and 27 are operated, and the air mix door 28 is in a state of adjusting the ratio of the air blown out from the indoor blower 27 to be blown to the radiator 4 in the heating heat exchange passage 3A. Thereby, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4. Since the air in the air flow path 3 is ventilated to the radiator 4, the air in the air flow path 3 is heated by the high-temperature refrigerant in the radiator 4, while the refrigerant in the radiator 4 is cooled by the air depriving heat, and condensed and liquefied.

The refrigerant discharged from the radiator 4 reaches the outdoor expansion valve 6 via the refrigerant pipe 13E, passes through the outdoor expansion valve 6 controlled to be opened, and flows into the outdoor heat exchanger 7. The refrigerant flowing into the exterior heat exchanger 7 is condensed by traveling or by being cooled by the outside air ventilated by the exterior fan 15. The refrigerant flowing out of the exterior heat exchanger 7 flows from the refrigerant pipe 13A through the electromagnetic valve 17 into the receiver/dryer section 14 and the subcooling section 16 in this order. Here, the refrigerant is supercooled.

The refrigerant that has come out of the subcooling portion 16 of the exterior heat exchanger 7 passes through the check valve 18, enters the refrigerant pipe 13B, passes through the interior heat exchanger 19, and reaches the indoor expansion valve 8. The refrigerant is decompressed by the indoor expansion valve 8, flows into the heat absorber 9, and evaporates. Due to the heat absorption action at this time, moisture in the air blown out from the indoor fan 27 condenses and adheres to the heat absorber 9, so that the air is cooled and dehumidified.

The refrigerant evaporated by the heat absorber 9 repeats the following cycle: the refrigerant passes through the internal heat exchanger 19 and the evaporation pressure adjustment valve 11 in this order, reaches the accumulator 12 through the refrigerant pipe 13C, and is sucked into the compressor 2. The air cooled and dehumidified by the heat absorber 9 is reheated (lower in heat radiation capacity than during heating) while passing through the radiator 4, and thus, dehumidified and cooled air in the vehicle interior is cooled.

The controller 32 controls the rotation 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 controls the valve opening degree of the outdoor expansion valve 6 based on the high-pressure of the refrigerant circuit R, thereby controlling the refrigerant pressure of the radiator 4 (radiator pressure PCI).

(5) Cold air mode

Next, in the cold air mode, the controller 32 fully opens the valve opening degree of the outdoor expansion valve 6 in the dehumidification cold air mode. Thereby, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4. The air in the air flow path 3 is not ventilated to the radiator 4, and therefore passes only therethrough, and the refrigerant coming out of the radiator 4 passes through the refrigerant pipe 13E to reach the outdoor expansion valve 6. At this time, since the outdoor expansion valve 6 is fully opened, the refrigerant passes through the outdoor expansion valve 6, passes through the refrigerant pipe 13J, flows into the outdoor heat exchanger 7, and is cooled by the outside air blown by the outdoor fan 15 or traveling, thereby being condensed and liquefied. The refrigerant flowing out of the exterior heat exchanger 7 flows from the refrigerant pipe 13A through the electromagnetic valve 17 into the receiver/dryer section 14 and the subcooling section 16 in this order. Here, the refrigerant is supercooled.

The refrigerant that has come out of the subcooling portion 16 of the exterior heat exchanger 7 passes through the check valve 18, enters the refrigerant pipe 13B, passes through the interior heat exchanger 19, and reaches the indoor expansion valve 8. The refrigerant is decompressed by the indoor expansion valve 8, flows into the heat absorber 9, and evaporates. By the heat absorption action at this time, moisture in the air blown out from the indoor fan 27 condenses and adheres to the heat absorber 9, so the air is cooled.

The refrigerant evaporated by the heat absorber 9 repeats the following cycle: the refrigerant passes through the internal heat exchanger 19 and the evaporation pressure adjustment valve 11 in this order, passes through the refrigerant pipe 13C, reaches the accumulator 12, and is sucked into the compressor 2. The air cooled and dehumidified by the heat absorber 9 is blown out into the vehicle interior from the respective air outlets 29A to 29C without passing through the radiator 4, and thus becomes cool air for the vehicle interior. In this cold air mode, the controller 32 controls the rotation 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.

(6) Auxiliary heater individual mode

In addition, the controller 32 of the embodiment has the following auxiliary heater-only mode in the case where excessive frost formation occurs at the outdoor heat exchanger 7, or the like: the compressor 2 and the outdoor fan 15 of the refrigerant circuit R are stopped, the auxiliary heater 23 is energized, and the vehicle interior is heated only by the auxiliary heater 23. In this case, the controller 32 also controls energization (heat generation) of the sub-heater 23 based on the sub-heater temperature Tptc detected by the sub-heater temperature sensor 50 and the aforementioned target heater temperature TCO.

The controller 32 operates the indoor fan 27, and the air mixing damper 28 ventilates the air in the airflow path 3 blown out from the indoor fan 27 to the sub-heater 23, thereby adjusting the air volume. The air heated by the auxiliary heater 23 is blown out into the vehicle interior from the air outlets 29A to 29C, and thus, the vehicle interior is warmed.

(7) Switching of operation modes

The controller 32 calculates the target outlet air temperature TAO according to the following formula (I). The target outlet temperature TAO is a target value of an outlet temperature TAI, which is a temperature of air blown out into the vehicle interior from the air outlets 29A to 29C.

TAO＝(Tset-Tin)×K＋Tbal(f(Tset、SUN、Tam))

　　　　　　　　　　　　　　　　　　　　・・(I)

Here, Tset is a set temperature in the vehicle interior set by the air-conditioning operation unit 53, Tin is a temperature of the vehicle interior air detected by the interior air temperature sensor 37, K is a coefficient, and Tbal is a balance value calculated from the set temperature Tset, the amount of insolation SUN detected by the insolation sensor 51, and the exterior air temperature Tam detected by the exterior air temperature sensor 33. In general, the target outlet air temperature TAO is set such that the lower the outside air temperature Tam, the higher the target outlet air temperature TAO, and the lower the target outlet air temperature TAO as the outside air temperature Tam increases.

At the time of startup, the controller 32 selects any one of the above-described operation modes based on the outside air temperature Tam detected by the outside air temperature sensor 33 and the target outlet air temperature TAO. After the start, the operation modes are selected and switched according to changes in the environment and the setting conditions such as the outside air temperature Tam and the target outlet air temperature TAO. However, when the DEF air blowing mode T is selected, switching to the heating mode and fixing of the operation mode are performed as described below.

(8) Auxiliary heating of auxiliary heater 23

When determining that the heating capacity of the heat radiator 4 is insufficient in the heating mode, the controller 32 energizes the auxiliary heater 23 to generate heat, thereby heating the auxiliary heater 23. When the auxiliary heater 23 generates heat, the air passing through the radiator 4 of the air flow passage 3 is further heated by the auxiliary heater 23.

Thus, when the heating capacity that can be generated by the radiator 4 is insufficient for the required heating capacity (calculated from the difference between the target radiator temperature TCO and the heat absorber temperature Te obtained from the target outlet air temperature TAO), the insufficient heating capacity is supplemented by the auxiliary heater 23.

(9) Control of the compressor 2 and the outdoor expansion valve 6 in the heating mode, the dehumidification heating mode

Next, the rotation speed NC of the compressor 2 and the valve opening degree control of the outdoor expansion valve 6 in the heating mode and the dehumidification heating mode will be described with reference to fig. 3 and 4. Fig. 3 is a control block diagram of the controller 32 that determines the target rotation speed TGNCh of the compressor 2 (compressor target rotation speed) in the heating mode and the dehumidification heating mode. The F/F (feed forward) operation amount calculation unit 58 of the controller 32 calculates the F/F operation amount TGNChff of the compressor target rotation speed based on the outside air temperature Tam obtained from the outside air temperature sensor 33, the blower voltage BLV of the indoor blower 27, the air mixing damper opening degree SW of the air mixing damper 28 obtained by SW ═ TAO-Te)/(TCI-Te, the target supercooling degree TGSC that is the target value of the supercooling degree SC at the outlet of the radiator 4, the target radiator temperature TCO that is the target value of the temperature of the radiator 4, and the target radiator pressure PCO that is the target value of the pressure of the radiator 4.

The opening degree SW of the air mixing damper is changed in the range of 0 to 1, and the air mixing fully closed state in which the air is not blown to the radiator 4 and the auxiliary heater 23 is set at 0, and the air mixing fully open state in which all the air in the air flow path 3 is blown to the radiator 4 and the auxiliary heater 23 is set at 1.

The target radiator pressure PCO calculates a target value calculation unit 59 based on the target supercooling degree TGSC and the target radiator temperature TCO. Further, the F/B (feedback) manipulated variable calculating unit 60 calculates the F/B manipulated variable TGNChfb of the target compressor rotation speed based on the target radiator pressure PCO and the radiator pressure PCI that is the refrigerant pressure of the radiator 4. The F/F manipulated variable TGNCnff calculated by the F/F manipulated variable calculation unit 58 and TGNChfb calculated by the F/B manipulated variable calculation unit 60 are added by an adder 61, and the limits of the control upper limit value and the control lower limit value are given by a limit setting unit 62, and then the sum is determined as the compressor target rotation speed TGNCh. The controller 32 controls the rotation speed NC of the compressor 2 based on the compressor target rotation speed TGNCh in the heating mode and the dehumidification heating mode.

That is, the controller 32 calculates the compressor target rotation speed TGNCh based on the radiator pressure PCI and the target radiator pressure PCO so that the radiator pressure PCI becomes the target radiator pressure PCO in the heating mode and the dehumidification-heating mode, and controls the rotation speed NC of the compressor 2.

Next, fig. 4 is a control block diagram of the controller 32 that determines the target opening degree TGECCVte of the outdoor expansion valve 6 (target opening degree of the outdoor expansion valve) in the dehumidification-air heating mode. The F/F operation amount calculation unit 65 of the controller 32 calculates an F/F operation amount TGECCVteff of the target opening degree of the outdoor expansion valve based on the target heat absorber temperature TEO of the heat absorber 9, the target radiator temperature TCO, the mass air flow rate Ga of the air, and the outside air temperature Tam.

Further, the F/B manipulated variable calculator 63 calculates the F/B manipulated variable TGECCVtefb of the target opening degree of the outdoor expansion valve based on the target heat absorber temperature TEO and the heat absorber temperature Te. The F/F manipulated variable TGECCVteff calculated by the F/F manipulated variable calculation unit 65 and the F/B manipulated variable TGECCVtefb calculated by the F/B manipulated variable calculation unit 63 are added by an adder 66, and the control upper limit value and the control lower limit value are limited by a limit setting unit 67, and then the target opening tgeccvtte of the outdoor expansion valve is determined. In the dehumidification heating mode, the controller 32 controls the valve opening degree of the outdoor expansion valve 6 based on the target opening degree TGECCVte of the outdoor expansion valve.

That is, in the dehumidification-air heating mode, the controller 32 calculates the target opening TGECCVte of the outdoor expansion valve based on the heat absorber temperature Te and the target heat absorber temperature TEO so that the heat absorber temperature Te becomes the target heat absorber temperature TEO, and controls the valve opening of the outdoor expansion valve 6. In this case, when the heat absorber temperature Te becomes higher than the target heat absorber temperature TEO, the target opening TGECCVte of the outdoor expansion valve is decreased, and the valve opening of the outdoor expansion valve 6 is decreased in a direction to increase the amount of refrigerant flowing into the heat absorber 9 through the refrigerant pipes 13F and 13B. Conversely, when the heat absorber temperature Te becomes lower than the target heat absorber temperature TEO, the target opening TGECCVte of the outdoor expansion valve increases, and the valve opening of the outdoor expansion valve 6 is increased in a direction to decrease the amount of refrigerant flowing into the heat absorber 9.

In this way, the controller 32 increases the target opening TGECCVte of the outdoor expansion valve and increases the valve opening of the outdoor expansion valve 6 as the heat absorber temperature Te becomes lower than the target heat absorber temperature TEO in the dehumidification heating mode, thereby reducing the amount of refrigerant flowing into the heat absorber 9 through the refrigerant pipes 13F and 13B, but for example, in the dehumidification heating mode, when the DEF button 53A provided in the air conditioning operation unit 53 is turned on by a rider during operation, the operation mode is switched to the heating mode.

(10) Operation mode control when DEF blowing mode is selected

That is, for example, when the DEF button 53A of the air conditioning operation unit 53 is turned on during operation in the dehumidification warm air mode and the air blowing mode is switched to the DEF air blowing mode, the controller 32 forcibly switches the operation mode to the warm air mode, and performs control to fix the operation mode to the warm air mode (prohibit switching of the operation mode). Thus, while the DEF button 53A is on and in the DEF blowing mode, switching from the heating mode to another operation mode such as the dehumidification heating mode is not performed.

In the warm air mode when the DEF air blowing mode is selected, the controller 32 corrects the target air-out temperature TAO calculated according to the above equation (I) to a predetermined value (e.g., several deg) higher, and increases the air volume of the indoor fan 27 as described above. In the DEF air blowing mode, the controller 32 causes the DEF air outlet 29C to be substantially fully opened by the DEF air outlet damper 31C, and the other air outlets 29A and 29B are closed by the respective air outlet dampers 31A and 31B.

In this way, the flow of the refrigerant in the refrigerant circuit R is in the warm air mode, and since the target outlet air temperature TAO is increased and the radiator temperature TCI is also increased, the indoor air blower 27 whose temperature is high is blown strongly from the DEF outlet port 29C to the inside of the front window 70 and the inside of the side window.

This makes the temperature of the front window 70, the side window itself, and the air in the vehicle interior inside the front window 70 and the like quickly become the dew point temperature or higher, and the mist inside the front window 70 and the like is quickly eliminated. In this case, since the heat absorber 9 does not perform dehumidification unlike the dehumidification heating mode, the operating efficiency of the compressor 2 is also improved.

As described above, in the present invention, when the DEF blowing mode for blowing air supplied into the vehicle interior at least to the inside of the front window 70 of the vehicle is selected, the controller 32 performs the heating mode in which the refrigerant discharged from the compressor 2 is radiated by the radiator 4, the radiated refrigerant is decompressed, and the refrigerant is absorbed heat only by the exterior heat exchanger 7, so that the temperature of the vehicle interior air inside the front window 70 and the like can be quickly and efficiently brought to the dew point temperature or higher, and the fog such as the front window 70 and the like can be eliminated.

In this case, since dehumidification by the heat absorber 9 is not performed as in the dehumidification heating mode, the problem of deterioration of the operation efficiency is avoided, the mist such as the front window 70 is efficiently eliminated, and the power consumption in the DEF blowing mode can be reduced.

Further, when the DEF air blowing mode is selected, the controller 32 raises the target air blowing temperature TAO as compared to when the other air blowing mode is selected, and therefore, is heated by the radiator 4 in the heating mode, and the temperature of the air blown out to the inside of the front window 70 and the like in the DEF air blowing mode is raised, so that the mist of the front window 70 and the like can be quickly eliminated.

Further, when the DEF blowing mode is selected in a state where the operation mode other than the heating mode is operated, the controller 32 switches to the heating mode, and therefore, compared to the dehumidification heating mode, it is possible to efficiently remove the fog such as the front window 70.

In this case, since the controller 32 fixes the operation mode to the heating mode in the DEF blowing mode, even in the state where the DEF blowing mode is present, it is possible to avoid a problem that the operation mode is switched to an operation mode other than the heating mode.

Example 2

Here, the configuration of the refrigerant circuit R described in the above embodiment is not limited to this, and can be changed without departing from the spirit of the present invention. For example, fig. 5 shows a refrigerant circuit R of another embodiment of the vehicle air-conditioning apparatus 1. In the figure, the same or similar functions are denoted by the same reference numerals as those in fig. 1. In this embodiment, the refrigerant pipe 13F and the solenoid valve 22 are not provided, the refrigerant pipe 13E is connected to the refrigerant pipe 13J, and the outdoor expansion valve 6 is connected to the refrigerant pipe 13J. The non-return valve 18 is not present at the outlet of the subcooling portion 16, and is connected to the refrigerant pipe 13B in this state.

An electromagnetic valve 30 (constituting a flow path switching device) that is closed when dehumidifying warm air and MAX cold air, which will be described later, are disposed in the refrigerant pipe 13G between the discharge side of the compressor 2 and the inlet side of the radiator 4. In this case, the refrigerant pipe 13G branches into a bypass pipe 35 at the upstream side of the solenoid valve 30, and the bypass pipe 35 is connected to the refrigerant pipe 13J at the downstream side of the outdoor expansion valve 6 via a solenoid valve 40 (which also constitutes a flow path switching device) that is opened at the time of dehumidification heating and MAX cooling. The bypass pipe 35, the solenoid valve 30, and the solenoid valve 40 constitute a bypass device 45.

By constituting the bypass device 45 by the bypass pipe 35, the solenoid valve 30, and the solenoid valve 40, as described later, it is possible to smoothly switch between a dehumidification heating mode in which the refrigerant discharged from the compressor 2 is directly flowed into the exterior heat exchanger 7, a MAX cooling mode, a heating mode in which the refrigerant discharged from the compressor 2 is flowed into the radiator 4, a dehumidification cooling mode, and a cooling mode. In this embodiment, the auxiliary heater 23 is provided in the airflow path 3 on the windward side (air upstream side) of the radiator 4 with respect to the flow of air in the airflow path 3. Further, in this embodiment, the evaporation pressure adjustment valve 11 is not provided.

In the above configuration, the operation of the vehicle air-conditioning apparatus 1 according to the embodiment will be described. In this embodiment, the controller 32 switches the operation modes among the warm air mode, the dehumidification cool air mode, the MAX cool air mode (maximum cool air mode), and the auxiliary heater individual mode to be executed (the internal circulation mode does not exist in this embodiment). The operation and the flow of the refrigerant when the warm air mode, the dehumidification cooling air mode, and the cooling air mode are selected, and the auxiliary heater single mode are the same as those in the above-described embodiment (embodiment 1), and the description thereof is omitted. However, in this embodiment (embodiment 2), the solenoid valve 30 is opened and the solenoid valve 40 is closed in the warm air mode, the dehumidification cooling air mode, and the cooling air mode. Note that the blowing modes are also the same, and therefore, the description thereof is omitted.

(11) Dehumidification and heating mode of vehicle air-conditioning apparatus 1 of fig. 5

On the other hand, when the dehumidification-air heating mode is selected, in this embodiment (embodiment 2), the controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21. The solenoid valve 30 is closed, the solenoid valve 40 is opened, and the valve opening degree of the outdoor expansion valve 6 is fully closed. Then, the compressor 2 is operated. The controller 32 operates the fans 15 and 27, and the air mix door 28 is in a state of ventilating the auxiliary heater 23 and the radiator 4 of the heating heat exchange path 3A with substantially all of the air blown out from the indoor fan 27 and passing through the air flow path 3 of the heat absorber 9, but also adjusts the air volume.

Thus, 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 flowing toward the radiator 4, and passes through the solenoid valve 40 to reach the refrigerant pipe 13J on the downstream side of the outdoor expansion valve 6. At this time, the outdoor expansion valve 6 is fully closed, and thus the refrigerant flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is cooled and condensed by traveling or by the outside air ventilated by the outdoor fan 15. The refrigerant flowing out of the exterior heat exchanger 7 flows from the refrigerant pipe 13A through the electromagnetic valve 17 into the receiver/dryer section 14 and the subcooling section 16 in this order. Here, the refrigerant is supercooled.

The refrigerant that has come out of the subcooling portion 16 of the exterior heat exchanger 7 enters the refrigerant pipe 13B and passes through the interior heat exchanger 19 to reach the indoor expansion valve 8. The refrigerant is decompressed by the indoor expansion valve 8, flows into the heat exchanger 9, and evaporates. The air blown out from the indoor fan 27 is cooled by the heat absorption action at this time, and the moisture in the air condenses and adheres to the heat absorber 9, so that the air in the airflow passage 3 is cooled and dehumidified. The refrigerant evaporated by the heat absorber 9 repeats the following cycle: passes through the internal heat exchanger 19, reaches the accumulator 12 through the refrigerant pipe 13C, and is sucked into the compressor 2.

At this time, since the valve opening degree of the outdoor expansion valve 6 is fully closed, it is possible to suppress or prevent a problem that the refrigerant discharged from the compressor 2 flows backward from the outdoor expansion valve 6 to the radiator 4. This can suppress or eliminate a decrease in the refrigerant circulation amount and ensure air conditioning performance. Further, the controller 32 in the dehumidification heating mode energizes the auxiliary heater 23 to generate heat. As a result, the air cooled and dehumidified by the heat absorber 9 is further heated and its temperature rises while passing through the auxiliary heater 23, and thus the vehicle interior is dehumidified and heated.

The controller 32 controls the rotation speed NC 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 the target heat absorber temperature TEO, which is a target value of the heat absorber temperature Te, and controls the energization of the sub-heater 23 (heating based on heat generation) based on the sub-heater temperature Tptc detected by the sub-heater temperature sensor 50 and the target radiator temperature TCO, thereby appropriately cooling and dehumidifying the air at the heat absorber 9 and reliably preventing a decrease in the temperature of the air blown out into the vehicle interior from the respective air outlets 29A to 29C by the heating of the sub-heater 23. Accordingly, the air blown into the vehicle interior can be dehumidified and the temperature thereof can be controlled to an appropriate heating temperature, thereby achieving comfortable and efficient dehumidification heating of the vehicle interior.

Further, 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, but the refrigerant does not flow to the radiator 4 in the dehumidification heating mode, and thus the problem that the radiator 4 absorbs heat from the air heated by the auxiliary heater 23 is also solved. That is, the temperature drop of the air blown into the vehicle interior by the radiator 4 is suppressed, and the COP is also improved.

(12) MAX Cool air mode (maximum Cool air mode) of air-conditioning apparatus 1 for vehicle shown in FIG. 5

In the MAX cooling mode, the controller 32 opens the solenoid valve 17 and closes the solenoid valve 21. The solenoid valve 30 is closed, the solenoid valve 40 is opened, and the valve opening degree of the outdoor expansion valve 6 is fully closed. Then, the compressor 2 is operated without supplying power to the auxiliary heater 23. The controller 32 operates the fans 15 and 27, and the air mixing damper 28 adjusts the ratio of the air blown out from the indoor fan 27 and passing through the air flow path 3 of the heat absorber 9 to be blown to the auxiliary heater 23 and the radiator 4 of the heating heat exchange path 3A.

Thus, 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 flowing toward the radiator 4, and passes through the solenoid valve 40 to reach the refrigerant pipe 13J on the downstream side of the outdoor expansion valve 6. At this time, the outdoor expansion valve 6 is fully closed, and thus the refrigerant flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is condensed by traveling or by being cooled by the outside air ventilated by the outdoor fan 15. The refrigerant flowing out of the exterior heat exchanger 7 flows from the refrigerant pipe 13A through the electromagnetic valve 17 into the receiver/dryer section 14 and the subcooling section 16 in this order. Here, the refrigerant is supercooled.

The refrigerant that has come out of the subcooling portion 16 of the exterior heat exchanger 7 enters the refrigerant pipe 13B and passes through the interior heat exchanger 19 to reach the indoor expansion valve 8. The refrigerant is decompressed by the indoor expansion valve 8, flows into the heat absorber 9, and evaporates. The air blown out from the indoor fan 27 is cooled by the heat absorption action at this time. Since moisture in the air condenses and adheres to the heat absorber 9, the air in the air flow path 3 is dehumidified. The refrigerant evaporated by the heat absorber 9 repeats the following cycle: passes through the internal heat exchanger 19, reaches the accumulator 12 through the refrigerant pipe 13C, and is sucked into the compressor 2. At this time, since the outdoor expansion valve 6 is fully closed, it is possible to similarly suppress or prevent a problem that the refrigerant discharged from the compressor 2 flows backward from the outdoor expansion valve 6 to the radiator 4. This can suppress or eliminate a decrease in the refrigerant circulation amount and ensure air conditioning performance.

Here, the refrigerant having a high temperature in the cooling mode flows to the radiator 4, so that a large amount of direct heat conduction from the radiator 4 to the HVAC unit 10 occurs, but the refrigerant does not flow to the radiator 4 in the MAX cooling mode, so that the air in the airflow passage 3 of the radiator 9 is not heated by the heat transferred from the radiator 4 to the HVAC unit 10. Therefore, strong cooling of the vehicle interior, particularly in an environment where the outside air temperature Tam is high, can be performed quickly in the vehicle interior, and comfortable air conditioning of the vehicle interior can be achieved. In the MAX cooling mode, the controller 32 also controls the rotation speed NC of the compressor 2 based on the temperature of the heat absorbers 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO, which is a target value thereof.

(13) Operation mode control when DEF blowing mode is selected in the embodiment of fig. 5

In this embodiment, as in the case of (10) described above, for example, the DEF button 53A of the air conditioning operation unit 53 is turned on during operation in the dehumidification heating mode, and when the blowing mode is switched to the DEF blowing mode, the controller 32 forcibly switches the operation mode to the heating mode, and performs control to fix the operation mode to the heating mode (to prohibit switching of the operation mode).

Similarly, in the warm air mode when the DEF air blowing mode is selected, the controller 32 corrects the target air-blowing temperature TAO calculated according to the above-described formula (I) to a predetermined value (e.g., the number deg) and to increase the air volume of the indoor fan 27 as described above. In this way, in this embodiment, the flow of the refrigerant in the refrigerant circuit R is also in the warm air mode, and the radiator temperature TCI is also increased by the increase in the target outlet air temperature TAO, so that air having a relatively high temperature is strongly blown from the DEF blow-off port 29C to the inside of the front window 70 and the inside of the side window by the indoor blower 27 whose speed is increased.

As a result, the temperature of the air in the vehicle interior inside the front window 70 and the like becomes the dew point temperature or higher, and therefore, the mist inside the front window 70 and the like is eliminated quickly. In this case, since the auxiliary heater 23 is not heated and the dehumidification is performed via the heat absorber 9 as in the dehumidification-air heating mode, a problem of deterioration in the operation efficiency of the vehicle air-conditioning apparatus 1 is avoided, the fog such as the front window 70 is effectively eliminated, and the power consumption in the DEF blowing mode can be significantly reduced.

In addition, in the above embodiment 1, the explanation is given by taking an example of switching the respective operation modes of the heating mode, the dehumidification heating mode, the internal circulation mode, the dehumidification cooling mode, the cooling mode, and the auxiliary heater individual mode, and in the embodiment 2, the explanation is given by taking an example of switching the respective operation modes of the heating mode, the dehumidification cooling mode, the MAX cooling mode, and the auxiliary heater individual mode.

In the embodiment, an example in which the DEF button 53A is turned on during operation in the dehumidification warm air mode is described, but the mode may be switched to the warm air mode when the DEF button 53A is turned on in the internal circulation mode, the dehumidification cool air mode, the cool air mode, and the MAX cool air mode.

Further, in the embodiment, the description has been made of the form in which the auxiliary heater 23 composed of the PTC heater is provided in the air flow path 3, but the present invention is not limited to this, and a water-air heat exchanger may be disposed in the air flow path 3, and the water heated by the heater may be circulated to the water-air heat exchanger via a circulation circuit to heat the air blown into the vehicle interior.

Description of the reference numerals

1 air conditioner for vehicle

2 compressor

3 air flow path

4 heat radiator

6 outdoor expansion valve

7 outdoor heat exchanger

8 indoor expansion valve

9 Heat absorber

22 magnetic valve (opening and closing valve)

23 auxiliary heater (auxiliary heating device)

29A to 29C air outlet

31A-31C outlet damper

32 controller (control device)

70 front window

R refrigerant circuit.

Claims (4)

1. An air conditioner for a vehicle, comprising a compressor, an air flow passage, a radiator, a heat absorber, an outdoor heat exchanger, a flow passage switching device, and a control device,

the compressor compresses the refrigerant and the refrigerant is compressed,

the air flow passage is used for the circulation of the air supplied to the vehicle interior,

the radiator heats the air supplied from the air passage to the vehicle interior by radiating heat from the refrigerant,

the heat absorber cools air supplied from the air flow passage into the vehicle interior by absorbing heat of a refrigerant,

the outdoor heat exchanger is arranged outside the vehicle,

the flow path switching device is used for switching the flow path of the refrigerant,

the aforementioned air-conditioning apparatus for a vehicle is characterized in that,

the control device controls the flow path switching device to switch between a heating mode in which the refrigerant discharged from the compressor is radiated by the radiator, the refrigerant after radiation is decompressed, and the refrigerant is absorbed by the outdoor heat exchanger, and a dehumidifying heating mode in which the refrigerant after radiation is decompressed by the radiator, and the refrigerant after radiation is absorbed by the heat absorber and the outdoor heat exchanger,

a DEF blowing mode for blowing air supplied into the vehicle interior at least to the inside of a front window of the vehicle,

when the DEF blowing mode is selected in a state where the dehumidification heating mode is operated, the mode is switched to the heating mode.

2. An air conditioner for a vehicle, comprising a compressor, an air flow passage, a radiator, a heat absorber, an outdoor heat exchanger, a flow passage switching device, an auxiliary heating device, and a control device,

the compressor compresses the refrigerant and the refrigerant is compressed,

the air flow passage is used for the circulation of the air supplied to the vehicle interior,

the radiator heats the air supplied from the air passage to the vehicle interior by radiating heat from the refrigerant,

the heat absorber cools air supplied from the air flow passage into the vehicle interior by absorbing heat of a refrigerant,

the outdoor heat exchanger is arranged outside the vehicle,

the flow path switching device is used for switching the flow path of the refrigerant,

the auxiliary heating device is used for heating the air supplied to the vehicle interior from the air circulation path,

the aforementioned air-conditioning apparatus for a vehicle is characterized in that,

the control device controls the flow path switching device to switch between a heating mode in which the refrigerant discharged from the compressor is radiated by the radiator and the refrigerant after radiation is decompressed and then absorbs heat by the outdoor heat exchanger, and a dehumidifying heating mode in which the refrigerant discharged from the compressor is made to flow to the outdoor heat exchanger without flowing to the radiator and the refrigerant after radiation is decompressed and then absorbs heat by the heat absorber and the auxiliary heating device generates heat,

has a DEF blowing mode for blowing air supplied into the vehicle interior at least to the inside of a front window of the vehicle,

when the DEF blowing mode is selected in a state where the dehumidification heating mode is operated, the mode is switched to the heating mode.

3. The air-conditioning apparatus for a vehicle according to claim 1 or 2,

the control device controls the operation of the compressor based on a target outlet air temperature TAO, which is a target value of the temperature of the air blown out into the vehicle interior, or a value derived from the target outlet air temperature TAO in the warm air mode, and has a plurality of outlet modes including the DEF outlet mode,

when the DEF blowing mode is selected, the target blowing temperature TAO is increased as compared to when the other blowing mode is selected.

4. The air-conditioning apparatus for a vehicle according to claim 1 or 2,

the control device fixes the operation mode to the heating mode in the DEF blowing mode.

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