Vehicle air conditioning

Abstract

A vehicle air conditioning system (1) comprising: a compressor (2) for compressing a coolant; an air flow duct (3) through which air flows to supply a vehicle interior; a radiator (4) through which the coolant can radiate heat, heating the air supplied to the interior of the vehicle through the air flow duct (3); a heat absorber (9) through which the coolant can absorb heat, wherein the air supplied to the interior of the vehicle through the air flow duct (3) is cooled; and a control unit (11), wherein the control unit (11) is arranged to to switch and execute a variety of operating modes to condition the air in the vehicle interior, wherein the control unit (11) is configured to calculate a heating temperature TH, which is a temperature of the air on a leeward side of the radiator (4), and to use the heating temperature TH in the control and to calculate the heating temperature TH using an approximate formula which varies depending on the set operating mode, wherein the control unit (11) is configured to perform a first-order calculation of a delay of a time constant Tau differently for calculating the heating temperature TH, depending on the set operating mode.

Description

Technical area

[0001] The present invention relates to a heat pump type air conditioning system which processes air in a vehicle interior. State of the art

[0002] Vehicle air conditioning systems and their operation are known from DE 11 2016 002 423 T5, US 5 983 989 A and DE 11 2013 005 367 T5.

[0003] Due to the increasing environmental problems in recent years, hybrid vehicles and electric vehicles have become more widespread. Consequently, as an air conditioner applicable to such a vehicle, an air conditioner has been developed, including an electric compressor for compressing and discharging a refrigerant, a radiator (condenser) provided within an airflow channel to allow the refrigerant to radiate heat, a heat absorber (evaporator) provided within the airflow channel to allow the refrigerant to absorb heat, and an external heat exchanger provided outside the vehicle interior to allow the refrigerant to radiate heat or absorb heat, and which switches and executes respective operation modes, such as a heating mode to heat the refrigerant discharged from the compressor.to radiate heat in the radiator and to absorb heat from the coolant from which heat was radiated in the radiator, a dehumidification and heating mode to radiate heat in the radiator and to absorb heat from the coolant from which heat was radiated in the heat absorber and the external heat exchanger, a dehumidification and cooling mode to radiate heat from the coolant from which heat was radiated in the radiator and the external heat exchanger, and to absorb heat from the heat-radiated coolant in the heat absorber, a cooling mode to radiate heat from the coolant from the compressor in the external heat exchanger and to absorb heat from the coolant in the heat absorber, etc.

[0004] Then, an air mixing damper is provided in the air flow passage, and the proportion of air passing through the radiator is adjusted by the air mixing damper from zero to the entire range, whereby a target value of the outlet temperature into the vehicle interior has been achieved (see, for example, Patent Document 1).

[0005] In this case, the interior of the airflow duct on the leeward side of the heat absorber is divided into a heater core duct and a bypass duct, and the radiator is arranged in the heater core duct. The air volume passing through the heater core duct is then adjusted by the air mixing damper. However, a parameter called the air volume ratio SW at which the air should pass through the heater core duct (radiator), which is obtained from the calculation formula SW = (TAO - Te) / (TH - Te), is used to control the air mixing damper in this case.

[0006] In this case, TAO is a target outlet temperature, TH is a temperature (a heating temperature TH, which will be described below) of the air on the leeward side of the radiator, Te is a temperature of the heat absorber, and the air volume ratio SW is calculated within 0 ≤ SW ≤ 1. "0" indicates a fully closed air mixing state in which the air is not passed through the heating heat exchange channel (radiator), and "1" indicates a fully open air mixing state in which all the air in the air flow channel is passed through the heating heat exchange channel (radiator). Furthermore, the above heating temperature TH was also used for switching each operation mode. Literature listPatent document:

[0007] Patent document 1: JP 2012 - 250 708 A Description of the invention Tasks to be solved by the invention

[0008] Here, the heating temperature TH, i.e., the temperature of the air on a downstream side of the above-described radiator, was previously estimated by a predetermined estimation formula without using a temperature sensor. However, there is a problem that, since a fixed estimation formula is set in the related art and a heating temperature TH was also calculated in each operation mode using this estimation formula, a difference between the estimated heating temperature and an actual temperature of the air on the downstream side of the radiator becomes large, thereby causing adverse effects on the temperature of the air blown into the vehicle interior.

[0009] The present invention has been developed to solve such conventional technical problems, and an object thereof is to appropriately estimate a heating temperature according to an operation mode and achieve comfortable vehicle interior air conditioning in a so-called heat pump type vehicle air conditioner. Means of solving the problem

[0010] A vehicle air conditioner of the present invention includes a compressor for compressing a coolant, an air flow passage through which air flows to supply a vehicle interior, a radiator through which the coolant can radiate heat, heating the air supplied to the vehicle interior through the air flow passage, a heat absorber through which the coolant can absorb heat, cooling the air supplied to the vehicle interior through the air flow passage, and a control unit, the control unit being configured to switch and execute a plurality of operation modes to condition the air of the vehicle interior.The vehicle air conditioning system is characterized in that the control unit is configured to calculate a heating temperature TH, which is a temperature of the air on a leeward side of the radiator, and to use the heating temperature TH in the control, and to calculate the heating temperature TH using an approximate formula that varies depending on the set operating mode. Furthermore, the vehicle air conditioning system is characterized in that the control unit is configured to perform a first-order calculation of a delay of a time constant Tau to calculate the heating temperature differently depending on the set operating mode.

[0011] The vehicle air conditioner of the invention according to claim 2 is characterized in that in the above invention, the control unit uses the heating temperature TH to calculate an air volume ratio SW at which the air is passed through the radiator and / or to switch the operation modes.

[0012] The vehicle air conditioner of the invention according to claim 3 is characterized in that in the above invention, the control unit is arranged to change the time constant Tau of the first-order delay according to a volumetric air volume Ga of the air flowing into the air flow passage.

[0013] The vehicle air conditioner according to claim 4 is characterized in that in the invention according to any one of claims 1 to 3, the control unit is arranged to calculate the heating temperature TH on the basis of a steady-state value TH0, which is a value of the heating temperature TH in a steady state, and the time constant Tau of the first-order delay.

[0014] The vehicle air conditioner of the invention according to claim 5 is characterized in that in the above invention, the vehicle air conditioner has an outdoor heat exchanger provided outside the vehicle interior, and in that the control unit has a dehumidifying and cooling mode in which the refrigerant discharged from the compressor flows from the radiator to the outdoor heat exchanger, the refrigerant in the radiator and the outdoor heat exchanger radiates heat, the heat-radiated refrigerant is decompressed, and the refrigerant in the heat absorber absorbs heat, and wherein in the dehumidifying and cooling mode, the control unit is configured to determine the steady-state value TH0 based on a saturation temperature THsatu of the refrigerant obtained from a refrigerant pressure of the radiator.

[0015] The vehicle air conditioner of the invention according to claim 6 is characterized in that in the invention according to claim 4 or 5, the vehicle air conditioner comprises an outdoor heat exchanger provided outside the vehicle interior, and in that the control unit has a cooling mode in which the coolant discharged from the compressor flows from the radiator into the outdoor heat exchanger, the coolant radiates heat in the outdoor heat exchanger, the heat-radiated coolant is decompressed, and the coolant then absorbs heat in the heat absorber, and wherein in the cooling mode, the control unit is configured to determine the steady-state value TH0 based on an average value of the coolant temperatures at an inlet and an outlet of the radiator.

[0016] The vehicle air conditioner of the invention according to claim 7 is characterized in that in the inventions of claims 4 to 6, the vehicle air conditioner comprises a bypass unit that lets the refrigerant discharged from the compressor directly into the outdoor heat exchanger without flowing to the radiator, and in that the control unit has a maximum cooling mode for letting the refrigerant discharged from the compressor flow into the outdoor heat exchanger through the bypass unit and radiate heat therein, decompressing the heat-radiated refrigerant, and then letting the refrigerant absorb heat in the heat absorber, and wherein in the maximum cooling mode, the control unit is configured to determine the steady-state value TH0 based on the average value of the coolant temperatures of the inlet and outlet of the radiator.

[0017] The vehicle air conditioning system of the invention according to claim 8 is characterized in that, in the inventions of claims 4 to 7, the control unit has a heating mode for letting the coolant discharged from the compressor flow into the radiator and radiate heat therein, decompressing the heat-radiated coolant, and then letting the coolant absorb heat in the external heat exchanger, wherein in the heating mode, the control unit is configured to correct the saturation temperature THsatu of the coolant, which is obtained from the coolant pressure of the radiator, by a predetermined correction value to determine the steady-state value TH0, and wherein the control unit is configured to determine the correction value from a supercooling degree SC of the coolant in the radiator and the volumetric air volume Ga of the air flowing into the air flow channel,or the volumetric air volume Ga and an air volume ratio SW with which the air is passed through the radiator.

[0018] The vehicle air conditioner of the invention according to claim 9 is characterized in that, in the inventions of claims 4 to 8, the vehicle air conditioner comprises: a bypass unit for letting the refrigerant discharged from the compressor flow directly into the exterior heat exchanger without flowing into the radiator;and an auxiliary heater for heating the air supplied from the air flow duct into the vehicle interior, and in that the control unit is configured to execute a dehumidification and heating mode to allow the coolant discharged from the compressor to flow into the exterior heat exchanger through the bypass unit and radiate heat therein, decompress the heat-radiated coolant, then allow the coolant to absorb heat in the heat absorber, and allow the auxiliary heater to generate heat, and wherein in the dehumidification and heating mode, the control unit is configured to determine the steady-state value TH0 based on a temperature Tptc of the auxiliary heater.;

[0019] The vehicle air conditioner of the invention according to claim 10 is characterized in that, in the inventions of claims 4 to 8, the control unit has a dehumidifying and heating mode for making the refrigerant discharged from the compressor radiate heat in the radiator, decompressing the heat-radiated refrigerant, and then making the refrigerant absorb heat only in the heat absorber, or in the heat absorber and the exterior heat exchanger, and wherein, in the dehumidifying and heating mode, the control unit is adapted to determine the steady-state value TH0 based on the saturation temperature THsatu of the refrigerant obtained from the refrigerant pressure of the radiator.

[0020] The vehicle air conditioner of the invention according to claim 11 is characterized in that, in the inventions of claims 4 to 10, the control unit is arranged to determine the steady-state value TH0 on the basis of the saturation temperature THsatu of the coolant obtained from the coolant pressure of the radiator, or the average value of the coolant temperatures of the inlet and the outlet of the radiator during an operation stop. Advantageous effect of the invention

[0021] According to the present invention, in a vehicle air conditioning system comprising a compressor for compressing a coolant, an air flow channel through which air flows to supply a vehicle interior, a radiator through which the coolant can radiate heat, wherein the air supplying the interior of the vehicle through the air flow channel is heated, a heat absorber through which the coolant can absorb heat, wherein the air supplying the interior of the vehicle through the air flow channel is cooled, and a control unit, wherein the control unit switches and executes a plurality of operation modes to condition the air of the vehicle interior.The vehicle air conditioning system is characterized in that the control unit calculates a heating temperature TH, which is the air temperature on the leeward side of the radiator, and uses the heating temperature TH for control. It calculates the heating temperature TH using an approximate formula that varies depending on the set operating mode. Therefore, it is possible to appropriately estimate the heating temperature TH according to the operating mode without using a special temperature sensor and use the heating temperature for control.

[0022] Therefore, for example, as in the invention of claim 2, when the control unit uses the heating temperature TH to calculate an air volume ratio SW at which the air is passed through the radiator and / or to switch the operation modes, the control unit minimizes a difference between the heating temperature and an actual temperature of the air on the leeward side of the radiator, and sufficiently controls the temperature of the air blown into the vehicle interior, thereby making it possible to achieve comfortable vehicle interior air conditioning.

[0023] Here, even when the operating mode is switched, the actual temperature of the air on the leeward side of the radiator does not change immediately. Therefore, as in the invention of claim 1, if the control unit for calculating the heating temperature performs a first-order calculation of a lag of a time constant Tau differently depending on the set operating mode, the heating temperature TH can be estimated so that it matches the actual temperature change of the air on the leeward side of the radiator.

[0024] In addition, the actual temperature change of the air on the leeward side of the radiator also varies depending on the amount of air flowing through the airflow channel. Therefore, as in the invention according to claim 3, when the control unit changes the time constant Tau of the first-order delay according to a volumetric air volume Ga of the air flowing into the airflow channel, it is possible to change a response speed in consideration of the volumetric air volume in the airflow channel and estimate an appropriate heating temperature TH.

[0025] Furthermore, as in the invention according to claim 4, in this case, when the control unit calculates the heating temperature TH on the basis of a steady-state value TH0 which is a value of the heating temperature TH in a steady state and the time constant Tau of the first-order delay, it is possible to estimate a heating temperature TH at which an actual temperature change from the steady-state value TH0 can be assumed.

[0026] For example, as in the invention according to claim 5, when an exterior heat exchanger provided outside the vehicle interior is further included and the control unit has a dehumidifying and cooling mode in which the coolant discharged from the compressor flows from the radiator to the exterior heat exchanger, the coolant in the radiator and the exterior heat exchanger radiates heat, the heat-radiated coolant is decompressed, and the coolant in the heat absorber absorbs heat, a heating temperature TH can be appropriately estimated from an average temperature of the radiator in consideration of a supercooling degree of the coolant in the radiator by determining the steady-state value TH0 in the dehumidifying and cooling mode based on a saturation temperature THsatu of the coolant obtained from a coolant pressure of the radiator.

[0027] In addition, as in the invention according to claim 6, when an outdoor heat exchanger is further included which is provided outside the vehicle interior, and the control unit has a cooling mode in which the coolant discharged from the compressor flows from the radiator into the outdoor heat exchanger, the coolant radiates heat in the outdoor heat exchanger, the heat-radiated coolant is decompressed, and the coolant then absorbs heat in the heat absorber, in the cooling mode, the steady-state value TH0 is determined based on an average value of the coolant temperature at an inlet and an outlet of the radiator.Consequently, since in the cooling mode the degree of subcooling is not applied to the coolant in the radiator, a heating temperature TH can be adequately estimated only by determining an average temperature of the radiator from the average value of the coolant temperature of the inlet and the outlet.

[0028] Furthermore, as in the invention according to claim 7, when a bypass unit is further provided which lets the refrigerant discharged from the compressor directly into the outdoor heat exchanger without flowing to the radiator, and the control unit has a maximum cooling mode for letting the refrigerant discharged from the compressor flow into the outdoor heat exchanger through the bypass unit and radiate heat therein, compressing the heat-radiated refrigerant, and then letting the refrigerant absorb heat in the heat absorber, a heating temperature TH can be appropriately estimated also in the maximum cooling mode in a similar manner by determining the steady-state value TH0 on the basis of the average value of the coolant temperature of the inlet and outlet of the radiator.

[0029] In addition, as in the invention according to claim 8, when the control unit has a heating mode to let the coolant discharged from the compressor flow into the radiator and radiate heat therein, decompress the heat-radiated coolant, and then let the coolant absorb heat in the outdoor heat exchanger, a heating temperature TH can be estimated also in the heating mode from an average temperature of the radiator in consideration of a supercooling degree of the coolant in the radiator by determining the steady state value TH0 on the basis of the saturation temperature THsatu of the coolant obtained from the coolant pressure of the radiator.In this case, since the saturation temperature THsatu also varies depending on the subcooling degree SC of the coolant in the radiator, the volumetric air volume Ga of the air flowing into the air flow channel, and the air volume ratio SW with which the air is passed through the radiator, especially in the heating mode, the heating temperature TH can be estimated more accurately by determining a correction value from these to correct the saturation temperature THsatu.

[0030] Furthermore, as in the invention according to claim 9, when further provided are a bypass unit for letting the coolant discharged from the compressor flow directly into the exterior heat exchanger without flowing into the radiator and an auxiliary heater for heating the air supplied from the air flow duct into the vehicle interior, and the control unit has a dehumidification and heating mode for letting the coolant discharged from the compressor flow into the exterior heat exchanger through the bypass unit and radiate heat therein, decompressing the heat-radiated coolant, then letting the coolant absorb heat in the heat absorber, and letting the auxiliary heater generate heat, a heating temperature, which is a temperature of the air on a leeward side of the radiator,can be accurately estimated by determining the steady-state value TH0 based on a temperature Tptc of the auxiliary heater in the dehumidification and heating mode.

[0031] Moreover, as in the invention according to claim 10, when the control unit has a dehumidifying and heating mode to make the refrigerant discharged from the compressor radiate heat in the radiator, decompress the heat-radiated refrigerant, and make the refrigerant absorb heat only in the heat absorber, or in the heat absorber and the exterior heat exchanger, in the dehumidifying and heating mode, a heating temperature TH can be accurately estimated from an average temperature of the radiator in consideration of a supercooling degree of the refrigerant in the radiator by determining the steady-state value TH0 based on a saturation temperature THsatu of the refrigerant obtained from the refrigerant pressure of the radiator.

[0032] Then, the control unit of the invention according to claim 11 determines the steady-state value TH0 on the basis of the saturation temperature THsatu of the coolant obtained from the coolant pressure of the radiator or the average value of the coolant temperature of the inlet and outlet of the radiator during an operation stop, thereby making it possible to smoothly resume control using a heating temperature TH when the operation is started next time. Short description of the drawings Fig. 1 is a schematic diagram of an air conditioner for vehicles of an embodiment to which the present invention is applied (Embodiment 1); Fig. 2 is a block diagram of a control unit of the vehicle air conditioning system of the Fig. 1; Fig. 3 is a typical diagram of an air flow duct of the vehicle air conditioning system according to Fig. 1; Fig. 4 is a control block diagram relating to the control of the compressor in a heating mode of a heat pump controller of the Fig. 2 Fig. 5 is a control block diagram relating to the control of the compressor in a dehumidification and heating mode of the heat pump controller of the Fig. 2; Fig. 6 is a control block diagram concerning the control of the auxiliary heater (auxiliary heater) in the dehumidification and heating mode of the heat pump controller of the Fig. 2; Fig. Figure 7 is a flowchart describing the control of the change of a time constant Tau by the heat pump controller of the Fig. 2; Fig. 8 is a diagram showing a change table of the time constant Tau corresponding to a volumetric air volume Ga; Fig. 9 is a graph showing a relationship between the outlet temperature and a saturation temperature of the radiator; Fig. 10 is a schematic diagram of an air conditioner for vehicles of another embodiment of the present invention (Embodiment 2). Method for carrying out the invention

[0033] Hereinafter, a detailed description will be given of embodiments of the present invention with reference to the drawings. [Embodiment 1]

[0034] Fig. 1 shows a schematic diagram of a vehicle air conditioner 1 of one embodiment of the present invention. A vehicle of the embodiment to which the present invention is applied is an electric vehicle (EV) in which a motor (an internal combustion engine) is not mounted, and which runs with an electric motor for propulsion driven by the energy stored in a battery (both not shown in the drawing), and the vehicle air conditioner 1 of the present invention is also driven by the energy of the battery.

[0035] Therefore, in an electric vehicle that cannot perform heating by engine waste heat, the vehicle air conditioner 1 of the embodiment performs a heating mode through a heat pump operation using a refrigerant cycle. Furthermore, the vehicle air conditioner 1 selectively performs respective operation modes of a dehumidifying and heating mode, a dehumidifying and cooling mode, a cooling mode, a MAX cooling mode (maximum cooling mode), and an auxiliary heater single mode.

[0036] Furthermore, the vehicle is not limited to electric vehicles, and the present invention is also effective for so-called hybrid vehicles, in which the engine is used together with the electric motor for propulsion. Furthermore, it goes without saying that the present invention is also applicable to a conventional car that runs on an engine.

[0037] The vehicle air conditioner 1 of the embodiment performs air conditioning (heating, cooling, dehumidification, and ventilation) of a vehicle interior of the electric vehicle. It includes an electric-type compressor 2 for compressing a refrigerant; a radiator 4 as a heater provided in an airflow duct 3 of an HVAC unit 10 in which the vehicle interior air is ventilated and circulated; a high-temperature, high-pressure refrigerant discharged from the compressor 2 flows therein via a refrigerant line 13G, and the refrigerant radiates heat therein to heat the air supplying the vehicle interior; an exterior expansion valve 6 (a pressure reduction unit) consisting of an electric valve that decompresses and expands the refrigerant during heating; and an exterior heat exchanger 7.which is provided outside the vehicle interior and which performs heat exchange between the refrigerant and the outside air to act as a radiator during cooling and as an evaporator during heating; an internal expansion valve 8 (a pressure reduction unit) consisting of an electric valve to decompress and expand the refrigerant; a heat absorber 9 provided in the air flow channel 3 to allow the refrigerant to absorb heat during cooling and dehumidification to cool the air sucked in from the interior and exterior of the vehicle and supplied to the vehicle interior; an accumulator 12, and others are sequentially connected through a refrigerant line 13, thereby forming a refrigerant circuit R.

[0038] Then, the coolant circuit R is filled with a predetermined amount of coolant and lubrication oil. Incidentally, an external fan 15 is provided in the external heat exchanger 7. The external fan 15 forcibly passes the outside air through the external heat exchanger 7, thereby performing heat exchange between the outside air and the coolant. The outside air is also passed through the external heat exchanger 7 while the vehicle is stationary (i.e., its speed is 0 km / h).

[0039] Furthermore, the exterior heat exchanger 7 has a receiver dryer unit 14 and a subcooling unit 16 sequentially on a coolant downstream side. A coolant line 13A extending from the exterior heat exchanger 7 is connected to the receiver dryer unit 14 via a spool valve 17, which is opened during cooling. A coolant line 13B on an outlet side of the subcooling unit 16 is connected to an inlet side of the heat absorber 9 via an internal expansion valve 8. Incidentally, the receiver dryer unit 14 and the subcooling unit 16 are structurally configured as a part of the exterior heat exchanger 7.

[0040] In addition, between the subcooling unit 16 and the internal expansion valve 8, a refrigerant line 13B is provided in a heat exchange arrangement with the refrigerant line 13C on an outlet side of the heat absorber 9, and both lines form an internal heat exchanger 19. Consequently, the refrigerant flowing into the internal expansion valve 8 through the refrigerant line 13B is cooled (subcooled) by the low-temperature refrigerant flowing out of the heat absorber 9.

[0041] In addition, the refrigerant line 13A extending from the exterior heat exchanger branches into a refrigerant line 13D, and this branched refrigerant line 13D communicates and is connected with the refrigerant line 13C on a downstream side of the internal heat exchanger 19 via a spool valve 21 opened during heating. The refrigerant line 13C is connected to the accumulator 12, and the accumulator 12 is connected to a refrigerant suction side of the compressor 2. Furthermore, a refrigerant line 13B on an outlet side of the radiator is connected to an inlet side of the exterior heat exchanger 7 via the exterior expansion valve 6.

[0042] Furthermore, a spool valve 30 (which constitutes a flow channel switching unit), which is closed during dehumidification, heating, and MAX cooling described below, is interposed in the refrigerant line 13G between an outlet side of the compressor 2 and an inlet side of the radiator 4. In this case, the refrigerant line 13G branches to a bypass line 35 on an upstream side of the spool valve 30. This bypass line 35 communicates and is connected to the refrigerant line 13E on a downstream side of the outdoor expansion valve 6 via a spool valve 40 (which also constitutes a flow channel switching unit), which is opened during dehumidification, heating, and MAX cooling. A bypass unit 45 is composed of this bypass line 35, spool valve 30, and spool valve 40.

[0043] The bypass unit 45 is composed of such a bypass line 35, a spool valve 30, and a spool valve 40, thereby making it possible to perform a smooth changeover between the dehumidifying and heating mode and the MAX cooling mode to allow the refrigerant discharged from the compressor 2 to flow directly into the outdoor heat exchanger 7, and the heating mode, the dehumidifying and cooling mode, and the cooling mode to allow the refrigerant discharged from the compressor 2 to flow into the radiator 4, as described below.

[0044] In addition, in the air flow channel 3, on an upstream side of the air of the heat absorber 9, respective intake ports such as an outside air intake port and an inside air intake port are formed (exemplified by an intake port 25 in Fig. 1). In the intake port 25, an intake changeover damper 26 is provided to change the air introduced into the airflow duct 3 between inside air, which is the air of the vehicle interior (an inside air recirculation mode), and outside air, which is the air outside the vehicle interior (an outside air introduction mode). Furthermore, on a downstream side of the intake changeover damper 26, an inside blower (a blower fan) 27 is provided to direct the introduced inside air or outside air into the airflow duct 3.

[0045] Furthermore, in Fig. 1, 23 denotes an auxiliary heater as an auxiliary heater (another heater) 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 airflow passage 3 on a windward side (upstream of the air) of the radiator 4 for flowing the air in the airflow passage 3. Then, when the auxiliary heater 23 is energized to generate heat, the air in the airflow passage 3, which flows into the radiator 4 via the heat absorber 9, is heated. Therefore, the auxiliary heater 23 becomes a so-called heater core to perform or supplement the heating of the vehicle interior. In the embodiment, the above-described radiator 4 and this auxiliary heater 23 become heaters.

[0046] Here, the airflow duct 3 on a leeward side (a downstream side), further downstream of the heat absorber 9 of the HVAC unit 10, is divided by a partition wall 10A to form a heater heat exchange duct 3A and a bypass duct 3B for bypassing it. The above-described radiator 4 and the auxiliary heater 23 are arranged in the heater heat exchange duct 3A.

[0047] In addition, an air mixing damper 28 is provided in the air flow duct 3 on a windward side of the auxiliary heater 23 to adjust a ratio at which the air (the inside air or outside air) in the air flow duct 3, which flows into the air flow duct 3 and is passed through the heat absorber 9, is passed through the heater heat exchange duct 3A in which the auxiliary heater 23 and the radiator 4 are arranged.

[0048] Furthermore, the HVAC unit 10 is formed on a leeward side of the radiator 4 with respective outlets: a feet outlet 29A, a ventilation outlet 29B, and an outlet 29C. The feet outlet 29A is an outlet for blowing air to the feet area of the vehicle interior and is located at the lowest position. Further, the ventilation outlet 29B is an outlet for blowing air near the chest or face of a driver in the vehicle interior and is positioned above the feet outlet 29A. Then, the outlet 29C is an outlet for blowing air to an inner surface of the windshield of the vehicle and is positioned at the highest position above the other outlets 29A and 29B.

[0049] Then, the feet outlet 29A, the ventilation outlet 29B and the outlet 29C are each equipped with a feet outlet damper 31A, a ventilation outlet damper 31B, and an outlet damper 31C for controlling the blow-out amount of air.

[0050] Next, Fig. 2 is a block diagram of a control unit 11 of the vehicle air conditioning system 1 of the embodiment. The control unit 11 is composed of an air conditioning controller 20 and a heat pump controller 32, both composed of a microcomputer, for example, a computer with a processor. These are connected to a vehicle communication bus 65, which forms a CAN (Controller Area Network) or a LIN (Local Interconnect Network). Furthermore, the compressor 2 and the auxiliary heater 23 are also connected to the vehicle communication bus 65. These air conditioning controller 20, heat pump controller 32, compressor 2, and auxiliary heater 23 are configured to transmit and receive data through the vehicle communication bus 65.

[0051] The air conditioning controller 20 is a higher-order controller that controls the vehicle's interior air conditioning. An input of the air conditioning controller 20 is connected to respective outputs of an outside air temperature sensor 33 that detects an outside air temperature (Tam) of the vehicle, an outside air humidity sensor 34 that detects an outside air humidity, an HVAC intake temperature sensor 36 that detects a temperature (an intake temperature Tas) of the air drawn from the intake port 25 into the airflow duct 3 and flowing into the heat absorber 9, an interior air temperature sensor 37 that detects a temperature (an interior air temperature Tin) of the air (the interior air) of the vehicle interior, an interior air humidity sensor 38 that detects a humidity of the air of the vehicle interior, and an interior air CO2 concentration sensor 39.which detects a carbon dioxide concentration of the vehicle interior, an outlet temperature sensor 41 which detects a temperature of the air to be blown into the vehicle interior, an outlet pressure sensor 42 which detects a refrigerant outlet pressure Pd (an outlet pressure Pd) of the compressor 2, a solar radiation sensor 51 of a photosensor system, for example, for detecting an amount of solar radiation into the vehicle, and a speed sensor 52 for detecting a moving speed (a speed) of the vehicle, and an air conditioning control unit 53 for setting the change of the predetermined temperature or the operating mode.

[0052] Furthermore, an output of the air conditioning controller 20 is connected to the outer blower 15, the inner blower (blower fan) 27, the intake change muffler 26, the air mixing muffler 28 and the respective exhaust mufflers 31A to 31C, and they are controlled by the air conditioning controller 20.

[0053] The heat pump controller 32 is a controller that essentially performs the control of the refrigerant circuit R. An input of the heat pump controller 32 is connected to the respective outputs of an outlet temperature sensor 43, which detects a temperature of the refrigerant discharged from the compressor 2, a suction pressure sensor 44, which detects a pressure of the refrigerant sucked into the compressor 2, a suction temperature sensor 55, which detects a temperature Ts of the refrigerant to be sucked into the compressor 2, a radiator outlet temperature sensor 46, which detects a coolant temperature (a radiator outlet temperature TCI) of an outlet of the radiator 4, a radiator inlet temperature sensor 46A, which detects a coolant temperature (a radiator inlet temperature TClin) of an inlet of the radiator 4, a radiator pressure sensor 47,which detects a coolant pressure (a radiator pressure PCI) of the radiator 4, a heat absorber temperature sensor 48 which detects a coolant temperature (a heat absorber temperature Te) of the heat absorber 9, a heat absorber pressure sensor 49 which detects a coolant pressure of the heat absorber 9, an auxiliary heater temperature sensor 50 which detects a temperature (an auxiliary heater temperature Tptc) of the auxiliary heater 23, an external heat exchanger temperature sensor 54 which detects a coolant temperature (an external heat exchanger temperature TXO) of the external heat exchanger 7, and an external heat exchanger pressure sensor 56 which detects a coolant pressure (an external heat exchanger pressure PXO) of the external heat exchanger 7.

[0054] Furthermore, an output of the heat pump controller 32 is connected to the respective spool valves of the outdoor expansion valve 6, the indoor expansion valve 8, the spool valve 30 (for reheating), the spool valve 17 (for cooling), the spool valve 21 (for heating), and the spool valve 40 (for bypass), and these are controlled by the heat pump controller 32. Incidentally, the compressor 2 and the auxiliary heater 23 have embedded controllers, and the controllers of the compressor 2 and the auxiliary heater 23 transmit and receive data to and from the heat pump controller 32 via the vehicle communication bus 65 and are controlled by the heat pump controller 32.

[0055] The heat pump controller 32 and the air conditioning controller 20 mutually transmit and receive data via the vehicle communication bus 65, and control respective devices based on the outputs of the respective sensors and the setting input by the air conditioning control part 53. However, in the case of this embodiment, the outputs of the outside air temperature sensor 33, the outlet pressure sensor 42, the speed sensor 52, and the air conditioning control part 53 are transmitted from the air conditioning controller 20 to the heat pump controller 32 through the vehicle communication bus 65 and are adapted to be provided for control by the heat pump controller 32.

[0056] With the above configuration, the operation of the vehicle air conditioner 1 of the embodiment will now be described. In this embodiment, the control unit 11 (the air conditioner controller 20 and the heat pump controller 32) executes and switches between the respective operating modes selected from the heating mode, the dehumidifying and heating mode, the dehumidifying and cooling mode, the cooling mode, the MAX cooling mode (maximum cooling mode), and the auxiliary heater single mode. First, a description will be given for an overview of the flow and control of the refrigerant in each operating mode. (1) Heating mode

[0057] When the heating mode is selected by the heat pump controller 32 (an automatic mode) or manual operation on the air conditioning control panel 53 (a manual mode), the heat pump controller 32 opens the spool valve 21 (for heating) and closes the spool valve 17 (for cooling). The heat pump controller 32 also opens the spool valve 30 (for reheating) and closes the spool valve 40 (for bypass). Then, the heat pump controller 32 operates the compressor 2. The air conditioning controller 20 operates the respective fans 15 and 27, and the air mixing damper 28 substantially has a state where all the air in the air flow duct 3, which is blown out from the indoor fan 27 and then flows over the heat absorber 9, is passed through the auxiliary heater 23 and the radiator 4 in the heater heat exchange duct 3A, but can regulate an air volume.Consequently, a high-temperature and high-pressure gaseous refrigerant discharged from the compressor 2 flows from the refrigerant line 13G into the radiator 4 via the spool valve 30. The air in the airflow passage 3 flows through the radiator 4, and thereby the air in the airflow passage 3 is heated by the high-temperature refrigerant in the radiator 4 (by the auxiliary heater 23 and the radiator 4 when the auxiliary heater 23 is operating). On the other hand, the refrigerant in the radiator 4 is deprived of heat by the air and is cooled to the point of condensation and liquefaction.

[0058] The liquefied refrigerant in the radiator 4 flows out of the radiator 4 and flows through the refrigerant line 13E to reach the outdoor expansion valve 6. The refrigerant flowing into the outdoor expansion valve 6 is decompressed therein and then flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 evaporates, and the heat is pumped by the outside air passed by the vent or the outdoor fan 15. In other words, the refrigerant circuit R functions as a heat pump. Then, the low-temperature refrigerant flowing out of the outdoor heat exchanger 7 flows through the refrigerant line 13A, the spool valve 21, and the refrigerant line 13D, and flows from the refrigerant line 13C into the accumulator 12 to undergo gas-liquid separation therein. Afterward, the gaseous refrigerant is sucked into the compressor 2, thereby repeating this cycle.The air heated by the radiator 4 (by the auxiliary heater 23 and the radiator 4 when the auxiliary heater 23 is operated) is blown out from the respective outlets 29A to 29C, and thus the heating of the vehicle interior is carried out.

[0059] The heat pump controller 32 calculates a target value of the radiator pressure PCO (a target value of the radiator pressure PCI) from a target value of the heater temperature TCO (a target value of the radiator outlet temperature TCI) calculated from a target value of the outlet temperature TAO by the air conditioning controller 20, and controls the number of revolutions NC of the compressor 2 based on the target value of the radiator pressure PCO and the refrigerant pressure (the radiator pressure PCI, ie, a high pressure of the refrigerant circuit R) of the radiator 4 detected by the radiator pressure sensor 47 to control heating by the radiator 4.Furthermore, the heat pump controller 32 controls a valve position of the outdoor expansion valve 6 based on the coolant temperature (the radiator outlet temperature TCI) of the outlet of the radiator 4 detected by the radiator outlet temperature sensor 46 and the radiator pressure PCI detected by the radiator pressure sensor 47, and controls a subcooling degree SC of the coolant in the outlet of the radiator 4.

[0060] Furthermore, when the heating capacity of the radiator 4 becomes less than the required heating capacity for air conditioning the vehicle interior in the heating mode, the heat pump controller 32 controls the power supply to the auxiliary heater 23 to supplement this shortage by generating heat from the auxiliary heater 23. Therefore, comfortable heating of the vehicle interior is achieved, and freezing of the exterior heat exchanger 7 is also suppressed. At this time, since the auxiliary heater 23 is arranged on an upstream airflow side of the radiator 4, the air flowing through the airflow duct 3 flows through the auxiliary heater 23 before the radiator 4. (2) Dehumidification and heating mode

[0061] Next, in the dehumidification and heating mode, the heat pump controller 32 opens the spool valve 17 and closes the spool valve 21. Further, the heat pump controller 32 closes the spool valve 30 and opens the spool valve 40, and completely closes the valve position of the outdoor expansion valve 6. After that, the heat pump controller 32 operates the compressor 2. The air conditioning controller 20 operates the respective fans 15 and 27, and the air mixing damper 28 substantially has a state where all the air in the air flow passage 3, which is blown out from the indoor fan 27 and then flows over the heat absorber 9, is passed through the auxiliary heater 23 and the radiator 4 into the heater heat exchange passage 3A, but also performs air volume adjustment.

[0062] Consequently, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 2 into the refrigerant line 13G flows into the bypass line 35 without flowing to the radiator 4, and reaches the refrigerant line 13E on the downstream side of the outdoor expansion valve 6 through the spool valve 40. 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 therein by the vehicle or the outside air introduced by the outdoor blower 15 to condense. The refrigerant flowing out of the outdoor heat exchanger 7 flows from the refrigerant line 13A through the spool valve 17 to sequentially flow into the receiver-drier unit 14 and the subcooling unit 16. There, the refrigerant is subcooled.

[0063] The refrigerant flowing out of the subcooling unit 16 of the outdoor heat exchanger 7 enters the refrigerant line 13B and reaches the indoor expansion valve 8 through the internal heat exchanger 19. After the refrigerant is decompressed in the indoor expansion valve 8, the refrigerant flows into the heat absorber 9 to evaporate. The air blown out by the indoor fan 27 is cooled by the heat absorption operation at this time, and the water in the air coagulates to adhere to the heat absorber 9, thereby cooling and dehumidifying the air in the airflow passage. The refrigerant evaporated in the heat absorber 9 flows through the internal heat exchanger 19 to reach the accumulator 12 via the refrigerant line 13C and is sucked into the compressor 2 through it, thereby repeating the circulation.

[0064] At this time, since the valve position of the outdoor expansion valve 6 is fully closed, 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. Therefore, a reduction in the refrigerant circulation amount is suppressed or eliminated to achieve that an air conditioning capacity is ensured.

[0065] Further, in the dehumidification and heating mode, the heat pump controller 32 supplies energy to the auxiliary heater 23 to generate heat. Consequently, the air cooled and dehumidified in the heat absorber 9 is further heated as it passes through the auxiliary heater 23, and the temperature rises, thus performing dehumidification and heating of the vehicle interior.

[0066] The heat pump controller 32 controls the number of revolutions of the compressor 2 based on a temperature (the heat absorber temperature Te) of the heat absorber 9, which is detected by the heat absorber temperature sensor 48, and a target value of the heat absorber temperature TEO, which is a target value of the heat absorber temperature Te, and is calculated by the air conditioning controller 20, and controls the power supply (heating by heat generation) of the auxiliary heater 23 based on the auxiliary heater temperature Tptc, which is detected by the auxiliary heater temperature sensor 50, and the above-described target value of the heater temperature TCO (which in this case becomes a target value of the auxiliary heater temperature Tptc), thereby appropriately preventing the temperature of the air discharged from the respective outlets 29A to 29C into the vehicle interior heated by the auxiliary heater 23 from decreasing.while appropriately cooling and dehumidifying the air by the heat absorber 9. Consequently, it is possible to control the temperature of the air blown into the vehicle interior to a suitable heating temperature while the air is being dehumidified, and to achieve comfortable and efficient dehumidification and heating of the vehicle interior.

[0067] Incidentally, since the auxiliary heater 23 is disposed on an airflow upstream side of the radiator 4, the air heated in the auxiliary heater 23 flows through the radiator 4, but in this dehumidifying and heating mode, the coolant is not caused to flow into the radiator 4. Therefore, the disadvantage that the radiator 4 absorbs heat of the air heated by the auxiliary heater 23 is also eliminated. That is, the temperature of the air blown into the vehicle interior is prevented from being lowered by the radiator 4, and a COP is also improved. (3) Dehumidification and cooling mode

[0068] Next, in the dehumidification and cooling mode, the heat pump controller 32 opens the spool valve 17 and closes the spool valve 21. Further, the heat pump controller 32 opens the spool valve 30 and closes the spool valve 40. Then, the heat pump controller 32 operates the compressor 2. The air conditioning controller 20 operates the respective fans 15 and 27, and the air mixing damper 28 substantially has a state of passing all the air in the air flow duct 3, which is blown out from the indoor fan 27 and then flows via the heat absorber 9 through the auxiliary heater 23 and the radiator 4 in the heater heat exchange duct 3A, but also makes an adjustment of an air volume.

[0069] Therefore, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 2 flows from the refrigerant line 13G into the radiator 4 via the spool valve 30. As the air in the air flow channel 3 flows through the radiator 4, the air in the air flow channel 3 is heated by the high-temperature refrigerant in the radiator 4, the refrigerant in the radiator 4 is extracted from the heat by the air, and is cooled to condense and liquefy.

[0070] The refrigerant flowing out of the radiator 4 flows through the refrigerant line 13E to reach the outdoor expansion valve 6, and flows through the outdoor expansion valve 6, which is controlled to open slightly to flow into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is cooled therein by the air or outside air, which is passed through the outdoor fan 15 to condense. The refrigerant flowing out of the outdoor heat exchanger 7 flows from the refrigerant line 13E through the spool valve 17 to flow sequentially into the receiver-drier unit 14 and the subcooling unit 16. There, the refrigerant is subcooled.

[0071] The refrigerant flowing out of the subcooling unit 16 of the outdoor heat exchanger 7 enters the refrigerant line 13B and flows through the internal heat exchanger 19 to reach the indoor expansion valve 8. The refrigerant is decompressed in the indoor expansion valve 8 and then flows into the heat absorber 9 to evaporate. The water in the air blown out by the indoor fan 27 coagulates to adhere to the heat absorber 9 due to the heat absorption operation at this time, and thus the air is cooled and dehumidified.

[0072] The refrigerant evaporated in the heat absorber 9 flows through the internal heat exchanger 19 to reach the accumulator 12 through the refrigerant line 13C, and flows therethrough to be sucked into the compressor 2, thereby repeating the circulation. Since the heat pump controller 32 does not power the auxiliary heater 23 in the dehumidification and cooling mode, the air cooled and dehumidified by the heat absorber 9 is reheated in the process of passing the radiator 4 (the radiant efficiency is lower than during heating). Therefore, dehumidification and cooling of the vehicle interior are performed.

[0073] The heat pump controller 32 controls the number of revolutions NC of the compressor 2 based on the temperature (the heat absorber temperature Te) of the heat absorber 9 detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO (input from the air conditioning controller 20) which is its target value. The heat pump controller 32 also calculates a target radiator pressure PCO from the above-described target heater temperature TCO, and controls the valve position of the outdoor expansion valve 6 based on the target radiator pressure PCO and the refrigerant pressure (the refrigerant pressure PCI, ie, a high pressure of the refrigerant circuit R) of the radiator 4 detected by the radiator pressure sensor 47, to control heating by the radiator 4. (4) Cooling mode

[0074] Next, in the cooling mode, the heat pump controller 32 fully opens the valve position of the outdoor expansion valve 6 in the above state of the dehumidification and cooling mode. Then, the heat pump controller 32 operates the compressor 2 and does not supply power to the auxiliary heater 23. The air conditioning controller 20 operates the respective fans 15 and 27, and the air mixing damper 28 is in a state where the ratio at which the air in the air flow duct 3, blown out from the indoor fan 27 and passed through the heat absorber 9, is passed through the auxiliary heater 23 and the radiator 4 into the heater heat exchange duct 3A is adjusted.Consequently, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 2 flows from the refrigerant line 13G into the radiator 4 through the spool valve 30, and the refrigerant flowing out of the radiator 4 flows through the refrigerant line 13E to reach the outdoor expansion valve 6. At this time, the outdoor expansion valve 6 is fully opened, and therefore, the refrigerant is passed therethrough and flows into the outdoor heat exchanger 7 as it is, where the refrigerant is air-cooled by the vehicle or the outside air passed through the outdoor fan 15 to condense and liquefy. The refrigerant flowing out of the outdoor heat exchanger 7 flows from the refrigerant line 13A through the spool valve 17 to sequentially flow into the receiver-drier unit 14 and the subcooling unit 16. There, the refrigerant is subcooled.

[0075] The refrigerant flowing out of the subcooling unit 16 of the outdoor heat exchanger 7 enters the refrigerant line 13B and reaches the indoor expansion valve 8 through the internal heat exchanger 19. The refrigerant is decompressed in the indoor expansion valve 8 and then flows into the heat absorber 9 to evaporate. The air blown out by the indoor fan 27 is cooled by the heat absorption operation at this time. Further, the water in the air coagulates to adhere to the heat absorber 9.

[0076] The refrigerant evaporated in the heat absorber 9 flows through the internal heat exchanger 19 to reach the accumulator 12 through the refrigerant line 13C, and flows therethrough to be sucked into the compressor 2, thereby repeating the circulation. The air cooled and dehumidified in the heat absorber 9 is blown out from the respective outlets 29A to 29C into the vehicle interior (part of which is passed through the radiator 4 to perform heat exchange), thereby performing the cooling of the vehicle interior. Further, in this cooling mode, the heat pump controller 32 controls the number of revolutions NC of the compressor 2 based on the temperature (the heat absorber temperature Te) of the heat absorber 9 detected by the heat absorber temperature sensor 48, and the above-described target value of the heat absorber temperature TEO is its target value. (5) MAX cooling mode (maximum cooling mode)

[0077] Next, in the MAX cooling mode, as a maximum cooling mode, the heat pump controller 32 opens the spool valve 17 and closes the spool valve 21. Further, the heat pump controller 32 closes the spool valve 30 and opens the spool valve 40, and completely closes a valve position of the outdoor expansion valve 6. Then, the heat pump controller 32 operates the compressor 2 and does not supply power to the auxiliary heater 23. The air conditioning controller 20 operates the respective blowers 15 and 27, and the air mixing damper 28 is in a state where the air in the air flow passage 3 is not passed through the auxiliary heater 23 and the radiator 4 into the heater heat exchange passage 3A. However, even if the air flows through a little, no problems arise.

[0078] Therefore, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 2 to the refrigerant line 13G flows into the bypass line 35 without flowing through the radiator 4, and reaches the refrigerant line 13B on a downstream side of the outdoor expansion valve 6 through the spool valve 40. 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 air-cooled therein by the vehicle or the outside air passed through the outdoor blower 15 to condense. The refrigerant flowing out of the outdoor heat exchanger 7 flows from the refrigerant line 13A through the spool valve 17 to sequentially flow into the receiver-drier unit 14 and the subcooling unit 16. Therein, the refrigerant is subcooled.

[0079] The refrigerant flowing out of the subcooling unit 16 of the outdoor heat exchanger 7 enters the refrigerant line 13B and reaches the indoor expansion valve 8 through the internal heat exchanger 19. The refrigerant is decompressed in the indoor expansion valve 8 and then flows into the heat absorber 9 to evaporate. The air blown out from the indoor fan 27 is cooled by the heat absorption operation at this time. Further, since the water in the air coagulates to adhere to the heat absorber 9, the air in the airflow channel 3 is dehumidified. Circulation is repeated in which the refrigerant evaporated in the heat absorber 9 flows through the internal heat exchanger 19 to reach the accumulator 12 via the refrigerant line 13C, and flows therethrough to be sucked into the compressor 2.At this time, since the outdoor expansion valve 6 is completely closed, it is possible to similarly suppress or prevent the disadvantage that the refrigerant discharged from the compressor 2 flows backward from the outdoor expansion valve 6 to the radiator 4. Thus, a reduction in the refrigerant circulation amount is suppressed or eliminated to achieve that an air conditioning capacity is ensured.

[0080] Since the high-temperature coolant flows into the radiator 4 in the cooling mode described above, direct heat conduction from the radiator 4 to the HVAC unit 10 occurs to a considerable extent. However, in the MAX cooling mode, since the coolant does not flow into the radiator 4, the air in the airflow duct 3 is not heated by the heat absorber 9 due to the heat transferred from the radiator 4 to the HVAC unit 10. Thus, strong cooling of the vehicle interior is performed, and in such an environment where the outside air temperature Tam is particularly high, the vehicle interior is quickly cooled, making it possible to achieve comfortable vehicle interior air conditioning.Further, even in the MAX cooling mode, the heat pump controller 32 controls the number of revolutions NC of the compressor 2 based on the temperature (the heat absorber temperature Te) of the heat absorber 9 detected by the heat absorber temperature sensor 48, and the above-described target value of the heat absorber temperature TEO is its target value. (6) Auxiliary heater single mode

[0081] Incidentally, the control unit 11 of this embodiment has an auxiliary heater single mode for cases where excessive frost occurs in the exterior heat exchanger 7 and others, in which the compressor 2 and the exterior blower 15 in the refrigerant circuit R are stopped, and the auxiliary heater 23 is energized to heat the vehicle interior only by the auxiliary heater 23. Also in this case, the heat pump controller 32 controls the energization (heat generation) of the auxiliary heater 23 based on the auxiliary heater temperature Tptc detected by the auxiliary heater temperature sensor 50 and the above-described target heater temperature TCO.

[0082] Further, the air conditioning controller 20 operates the interior blower 27, and the air mixing damper 28 is in a state where the air in the air flow passage 3, which is blown out from the interior blower 27, is guided into the heater heat exchange passage 3A through the auxiliary heater 23 to adjust an air volume. The air heated by the auxiliary heater 23 is blown out into the vehicle interior from the respective outlets 29A to 29C, thereby heating the vehicle interior. (7) Change of operating mode

[0083] The air conditioning controller 20 calculates the above-described target outlet temperature TAO from the following equation (I). The target outlet temperature TAO is a target temperature of the air blown into the vehicle interior. TAO=(Tset−Tin)×K+Tbal(f(Tset, SUN, Tam)) where Tset is a predetermined temperature of the vehicle interior set at the air conditioning control part 53, Tin is an internal temperature detected by the interior air temperature sensor 37, K is a coefficient, and Tbal is a balance value calculated from the predetermined value Tset, the solar radiation amount SUN detected by the solar radiation sensor 51, and the outside air temperature Tam detected by the outside air temperature sensor 33.

[0084] Furthermore, in general, the lower the outside air temperature Tam is, the higher the target value of the outlet temperature TAO becomes, and the target value of the outlet temperature TAO is decreased with increasing outside air temperature Tam.

[0085] The heat pump controller 32 selects an operation mode from the above respective operation modes based on the outside air temperature Tam (detected by the outside air temperature sensor 33) and the target outlet temperature TAO transmitted from the air conditioning controller 20 via the vehicle communication bus 65 at startup, and transmits the respective operation mode to the air conditioning controller 20 via the vehicle communication bus 65.Further, after starting, the heat pump controller 32 changes the respective operation mode based on parameters such as the outside air temperature Tam, the humidity of the vehicle interior, the target outlet temperature TAO, a heater temperature TH (a temperature of the air on a leeward side of the radiator 4, which is an estimated value) described below, the target heater temperature TCO, the heat absorber temperature Te, the target heat absorber temperature TEO, the presence or absence of a dehumidification request for the vehicle interior, etc.which appropriately switches between the heating mode, the dehumidification and heating mode, the dehumidification and cooling mode, the cooling mode, the MAX cooling mode, and the auxiliary heater single mode in consideration of the ambient conditions or the dehumidification request, to control the temperature blown into the vehicle interior to the target value of the outlet temperature TAO, thereby achieving comfortable and efficient air conditioning of the vehicle interior. (8) Control of compressor 2 in heating mode by the heat pump controller 32

[0086] Next, a detailed description will be given for controlling the compressor 2 in the heating mode described above using Fig. 4. Fig. 4 is a control block diagram of the heat pump controller 32, which determines a target value of the number of revolutions (a target value of the number of revolutions of the compressor) TGNCh of the compressor 2 for the heating mode.An F / F (feedforward) control amount calculation unit 58 of the heat pump controller 32 calculates an F / F control amount TGNChff of the target value of the number of revolutions of the compressor based on the outside air temperature Tam, which is determinable by the outside air temperature sensor 33, a fan voltage BLV of the indoor fan 27, an air volume ratio SW of the air mix damper 28, which is determinable from SW = (TAO - Te) / (TH - Te), a target value for the subcooling degree TGSC, which is a target value of the subcooling degree SC in the outlet of the radiator 4, the above-described target value of the heater temperature TCO (transmitted from the air conditioning controller 20), which is the target value of the temperature of the radiator 4, and the target value of the radiator pressure PCO, which is the target value of the pressure of the radiator 4.

[0087] The above temperature TH used to calculate the air volume ratio SW is a temperature (hereinafter referred to as heating temperature) of the air on a leeward side of the radiator 4. The heat pump controller 32 estimates the heating temperature TH from a first-order delay calculation formula (II) shown below: TH=(INTL×TH0+Tau×THz) / (Tau+INTL) where INTL is a calculation period (constant), Tau is a time constant of the first-order delay, TH0 is a steady-state value of the heating temperature TH before a first-order delay calculation, and THz is a previous value of the heating temperature TH. Estimating the heating temperature TH in this way eliminates the need for a dedicated temperature sensor.

[0088] Incidentally, the heat pump controller 32 changes the above time constant Tau and the steady-state value TH0 according to the above-described operating modes, thereby making the above-described approximate formula (II) different depending on the operating mode for estimating the heating temperature TH. However, this will be described in more detail below. The heating temperature TH is then transmitted to the air conditioning controller 20 via the vehicle communication bus 65.

[0089] The target value of the radiator pressure PCO is calculated by the target value calculation unit 59 based on the above target value of the subcooling degree TGSC and the target value of the heater temperature TCO. Further, an F / B (feedback) control amount calculation unit 60 calculates an F / B control amount TGNChfb of a target value of the number of revolutions of the compressor based on the target value of the radiator pressure PCO and the radiator pressure PCI, which is the refrigerant pressure of the radiator 4. Then, the F / F control amount TGNChff calculated by the F / F control amount calculating unit 58 and TGNChfb calculated by the F / B control amount calculating unit 60 are added in an adder 61, and the result is added with limits of an upper limit of control and a lower limit of control in a limit setting unit 62, followed by determining as a target value the number of revolutions of the compressor TGNCh.In the heating mode, the heat pump controller 32 controls the number of revolutions NC of the compressor 2 based on the target value of the number of revolutions of the compressor TGNCh. (9) Control of the compressor 2 and the auxiliary heater 23 in the dehumidification and heating mode by the heat pump controller 32

[0090] On the other hand, Fig. 5 is a control block diagram of the heat pump controller 32, which determines a target number of revolutions (a target number of revolutions of the compressor) TGNCc of the compressor 2 for the dehumidification and heating mode. The F / F control amount calculation unit 63 of the heat pump controller 32 calculates an F / F control amount TGNCcff of the target number of revolutions of the compressor based on an outside air temperature Tam, the volumetric air volume Ga of the air flowing in the airflow duct 3, a target radiator pressure PCO, which is a target pressure (radiator pressure PCI) of the radiator 4, and the target heat absorber temperature TEO, which is a target temperature (heat absorber temperature Te) of the heat absorber 9.

[0091] Further, the F / B control amount calculation unit 64 calculates an F / B control amount TGNCcfb of the target value of the number of revolutions of the compressor based on the target value of the heat absorber temperature TEO (transmitted from the air conditioning controller 20) and the heat absorber temperature Te. Then, the F / F control amount TGNCcff calculated by the F / F control amount calculation unit 63 and the F / B control amount TGNCcfb calculated by the F / B control amount calculation unit 64 are added in an adder 66, and the result thereof is added with limit values of an upper limit of control and a lower limit of control in a limit setting unit 67 and then determined as the target value of the number of revolutions of the compressor TGNCc. In the dehumidification and heating mode, the heat pump controller 32 controls the number of revolutions NC of the compressor 2 based on the target value of the number of revolutions of the compressor TGNCc.

[0092] Further is Fig. 6 shows a control block diagram of the heat pump controller 32, which determines the required capabilities of the auxiliary heater TGQPTC of the auxiliary heater 23 in the dehumidification and heating modes. The target heater temperature TCO and the auxiliary heater temperature Tptc are input to a subtractor 73 of the heat pump controller 32 to calculate a deviation (TCO - Tptc) between the target heater temperature TCO and the auxiliary heater temperature Tptc. The deviation (TCO - Tptc) is input to the F / B control unit 74. The F / B control unit 74 eliminates the deviation (TCO - Tptc) and calculates a required capability of the auxiliary heater F / B control amount so that the auxiliary heater temperature Tptc becomes equal to the target heater temperature TCO.

[0093] The required capability of the auxiliary heater F / B control amount calculated in the F / B control unit 74 is added to an upper control limit and a lower control limit in the limit setting unit 76, and then determined as the required capability of the auxiliary heater TGQPTC. In the dehumidification and heating mode, the controller 32 controls the power supply to the auxiliary heater 23 based on the required capability of the auxiliary heater TGQPTC, thereby controlling the heat generation (heating) of the auxiliary heater 23 so that the auxiliary heater temperature Tptc becomes equal to the target heater temperature TCO.

[0094] Therefore, in the dehumidification and heating mode, the heat pump controller 32 controls the operation of the compressor based on the heat absorber temperature Te and the target heat absorber temperature TEO, and controls the heat generation by the auxiliary heater 23 based on the target heater temperature TCO, thereby appropriately controlling the cooling and dehumidification by the heat absorber 9 and the heating by the auxiliary heater 23 in the dehumidification and heating mode.

[0095] Consequently, the temperature of the air can be controlled to a more accurate heating temperature because the air blown into the vehicle interior is better dehumidified, and more comfortable and efficient dehumidification and heating of the vehicle interior can be achieved. (10) Control of the air mixing damper 28

[0096] Next, a description will be given of the control of the air mixing damper 28 by the air conditioning controller 20 while referring to Fig. 3. In Fig. 3, Ga is a volumetric air volume of the air flowing into the above-described air flow channel 3, Te is a heat absorber temperature, and TH is the above-described heating temperature (, the temperature of the air on a leeward side of the radiator 4).

[0097] Based on the air volume ratio SW calculated by the equation (the following equation (III)) and passed through the radiator 4 and the auxiliary heater 23 into the heater heat exchange duct 3A as described above, the air conditioning controller 20 controls the air mixing damper 28 so that the air is brought to an air volume in the corresponding ratio, and thereby controls an amount of the air passed through the radiator 4 (and the auxiliary heater 23). SW=(TAO−Te) / (TH−Te)

[0098] That is, the air volume ratio SW at which the air is passed through the radiator 4 and the auxiliary heater 23 into the heater heat exchange channel 3A changes in a range of 0 less than or equal to SW less than or equal to 1. "0" indicates a fully closed state of air mixing in which all the air in the air flow channel 3 is passed through the bypass line 3B without passing through the heater heat exchange channel 3A, and "1" indicates a fully open state of air mixing in which all the air in the air flow channel 3 is passed through the heater heat exchange channel 3A. That is, the air volume to the radiator 4 becomes Ga × SW. (11) Estimation of the heating temperature TH in operating mode

[0099] As described above, the heating temperature TH, that is, the temperature of the air on a leeward side of the radiator 4, is calculated by the approximate formula (II) described above. Then, the heating temperature TH is used to calculate the air volume ratio SW at which the air is passed through the radiator 4 and for switching each operation mode in the air conditioning controller 20. However, as described above, the heat pump controller 32 calculates the heating temperature TH using an approximate formula that varies depending on the operation mode.

[0100] In this case, the heat pump controller 32 changes the time constant Tau and the steady-state value TH0 in the formula (II) depending on the operation mode to generate the approximate formula (II) that varies depending on the operation mode, and calculates the heating temperature TH by such an approximate formula that varies depending on the operation mode. This will be described below with reference to Figures 7 to 9. (11 - 1) Calculation of the heating temperature TH in the auxiliary heater single mode or when stopping the compressor 2 and the auxiliary heater 23

[0101] If the current operating mode is the auxiliary heater single mode described above (during PTC single operation in Fig. 7 and Fig. 8), or if the compressor 2 (HP in Fig. 7 and Fig. 8) and the auxiliary heater 23 (PTC in Fig. 7 and Fig. 8) are stopped, the heat pump controller 32 proceeds from step S1 to step S9 of the Fig. 7, to set the above-described time constant Tau to a time constant Tau0. In this case, the heat pump controller 32 determines the above-described steady-state value TH0 as the above-described auxiliary heater temperature Tptc. Incidentally, in this case, the heat pump controller 32 does not change the time constant Tau0 even if the above-described volumetric air volume Ga changes, and in this embodiment, the heat pump controller 32 sets the time constant to "10" (highest response speed) as shown in the time constant table of the Fig. 8 is shown.

[0102] Since a change in the temperature of the air on the leeward side of the radiator 4 occurs rapidly even in the auxiliary heater single mode or in a state where the compressor 2 and the auxiliary heater 23 are stopped, the heating temperature TH can be adapted to an actual change in the temperature of the air on a leeward side of the radiator 4 by setting the time constant Tau in the approximate formula TH = (INTL × TH0 + Tau × THz) / (Tau + INTL) to Tau0, which is a value with the highest response speed, as described above. Furthermore, since the temperature on a leeward side of the radiator 4 becomes equal to the auxiliary heater temperature Tptc in the auxiliary heater single mode or in the state where the compressor 2 and the auxiliary heater 23 are stopped, the heating temperature TH can be estimated accordingly by setting the steady-state value TH0 to the auxiliary heater temperature Tptc. (11 - 2) Calculation of the heating temperature TH at the beginning of a transition from the dehumidification and heating mode to the heating mode or during the start of the compressor 2

[0103] Next, when the transition from the dehumidification and heating mode to the heating mode begins, or when the compressor 2 is in the process of starting, the heat pump controller 32 proceeds from step S2 to step S10 of the Fig. 7 to determine that the above-described time constant Tau becomes a time constant Tau2. Further, the heat pump controller 32 determines the above-described steady-state value TH0 to the auxiliary heater temperature Tptc. Incidentally, in this case, the heat pump controller 32 does not change the time constant Tau2 even if the above-described volumetric air volume Ga changes, and in this embodiment, the heat pump controller 32 determines the time constant as "20" (the third fastest response speed) as shown in the time constant table of the Fig. 8 is shown.

[0104] The change in the temperature of the air on a leeward side of the radiator 4 occurs relatively slowly when the transition from the dehumidifying and heating mode to the heating mode begins, or in a state where the compressor 2 is starting. Therefore, the time constant Tau in the approximate formula of TH = (INTL × TH0 + Tau × THz) / (Tau + INTL) is set to Tau2, at which the response speed is the third fastest value, to thereby make it possible to adapt the heating temperature TH to the actual change in the temperature of the air on a leeward side of the radiator 4. Further, when the transition from the dehumidifying and heating mode to the heating mode begins, or in a state where the compressor 2 is starting, the temperature on the leeward side of the radiator 4 becomes the auxiliary heater temperature Tptc, and thus the steady-state value TH0 is set to the auxiliary heater temperature Tptc, whereby the heating temperature TH can be estimated accordingly. (11 - 3) Calculation of the heating temperature TH in the heating mode

[0105] Next, when the operation mode is the heating mode, the heat pump controller 32 proceeds from step S3 to step S11 of the Fig. 7 to determine the above-described time constant Tau to a time constant Tau1. Further, when the compressor 2 is in protective control, the heat pump controller 32 determines the above-described steady-state value TH0 as the auxiliary heater temperature Tptc, and on the other hand, the heat pump controller 32 determines the steady-state value TH0 based on a saturation temperature THsatu of the refrigerant, which is determinable from the radiator pressure PCI (the refrigerant pressure of the radiator 4). Incidentally, the protective control of the compressor 2 is a control in which the maximum value NCmax of the number of revolutions NC of the compressor 2 is limited in such a manner that the suction temperature of the refrigerant TS of the compressor 2 does not drop excessively.

[0106] The saturation temperature THsatu is determined from a table in Fig. 9. In the drawing, the horizontal axis is the radiator pressure PCI, and the vertical axis is the saturation temperature THsatu. The saturation temperature THsatu is an average temperature of the radiator 4 taking into account the subcooling degree SC of the coolant in the radiator 4. Further, the heat pump controller 32 corrects the saturation temperature THsatu by a predetermined correction value. The correction value is determined from the subcooling degree SC of the coolant in the radiator 4 and the volumetric air volume Ga of the air flowing into the airflow channel 3, or is determined from the volumetric air volume Ga and the air volume ratio SW at which the air is passed through the radiator 4.

[0107] Incidentally, in this case, the heat pump controller 32 does not change the time constant Tau1 even if the above-described volumetric air volume Ga changes, and in this embodiment, the heat pump controller 32 sets the time constant to “15” (the second fastest response speed) as shown in the time constant table of the Fig. 8. In the heating mode, the change in the temperature of the air on the leeward side of the radiator 4 occurs relatively quickly, and therefore, as described above, the time constant Tau in the approximate formula of TH = (INTL × TH0 + Tau × THz) / (Tau + INTL) is set to Tau1, at which the response speed is the second fastest value, thereby enabling the heating temperature TH to coincide with the actual change in the temperature of the air on a leeward side of the radiator 4.

[0108] Further, in the heating mode, in particular, the saturation temperature THsatu also changes depending on the supercooling degree SC of the coolant in the radiator 4, the volumetric air volume Ga of the air flowing into the air flow channel, and the air volume ratio SW at which the air is passed through the radiator 4, and therefore, a correction value is determined from these to correct the saturation temperature THsatu, whereby the heating temperature can be estimated more accurately. (11 - 4) Calculation of the heating temperature TH in the dehumidification and heating mode

[0109] Next, when the operation mode is the dehumidification and heating mode, the heat pump controller 32 proceeds from step S4 to step S12 of the Fig. 7 to determine the above-described time constant Tau to the time constant Tau2. Further, the heat pump controller 32 determines the above-described steady-state value TH0 as the auxiliary heater temperature Tptc. Incidentally, even in this case, the heat pump controller 32 does not change the time constant Tau2 regardless of the change in the volumetric air volume Ga, and in this embodiment, the heat pump controller 32 determines the time constant to "20" (the third fastest response speed) as shown in the time constant table of the Fig. 8 is shown.

[0110] As described above, since the change of the temperature of the air on a leeward side of the radiator 4 becomes relatively slow in the dehumidifying and heating mode, the time constant Tau in the approximate formula TH = (INTL × TH0 + Tau × THz) / (Tau + INTL) is set to Tau2, at which the response speed is the third fastest value, thereby enabling the heating temperature TH to coincide with the actual value of the temperature of the air on a leeward side of the radiator 4. Further, since the temperature on a leeward side of the radiator 4 becomes the auxiliary heater temperature Tptc in the dehumidifying and heating mode, the steady-state value TH0 is set to the auxiliary heater temperature Tptc, thereby enabling the heating temperature TH to be estimated accordingly. (11 - 5) Calculation of the heating temperature TH in the MAX cooling mode

[0111] Next, when the operation mode is the MAX cooling mode, the heat pump controller 32 proceeds from step S5 to step S13 of the Fig. 7 to set the above-described time constant Tau to a time constant Tau3. Further, the heat pump controller 32 determines the above-described steady-state value TH0 to an average value of the coolant inlet temperature TClin and the coolant outlet temperature TCI of the radiator 4 + a predetermined offset value. Incidentally, in this case, the heat pump controller 32 changes the time constant Tau3 according to the volumetric air volume GA. In this embodiment, as shown in the time constant table of the Fig. As shown in Figure 8, the heat pump controller 32 sets the time constant as "10" (the fastest response speed) when Ga is 500, sets the time constant as "20" (the third fastest response speed) when Ga is 400, sets the time constant as "30" (the second fastest response speed) when Ga is 300, and sets the time constant as "40" (the slowest response speed) when Ga is 200 or less. That is, the larger the volumetric air volume Ga, the faster the response speed is set, and the smaller the volumetric air volume Ga, the slower the response speed is set.

[0112] As described above, since the change in temperature of the air on a leeward side of the radiator 4 varies depending on the flow rate of the air in the air flow channel 3 in the MAX cooling mode, the time constant Tau in the approximate formula TH = (INTL × TH0 + Tau × THz) / (Tau + INTL) is changed depending on the volumetric air volume Ga, thereby enabling the heating temperature TH to coincide with the actual change in temperature of the air on a leeward side of the radiator 4. Further, in the MAX cooling mode, the degree of subcooling is not applied to the coolant in the radiator 4, and therefore, the average temperature of the radiator 4 is determined from the average value of the coolant inlet temperature TClin and the coolant outlet temperature TCI of the radiator 4 and is simply determined as the steady-state value TH0, thereby making it possible to estimate the heating temperature TH accordingly. (11 - 6) Calculation of heating temperature in dehumidification and cooling mode

[0113] Next, when the operation mode is in the dehumidification and cooling mode, the heat pump controller 32 proceeds from step S6 to step S14 of the Fig. 7 to determine the above-described time constant Tau to a time constant Tau3. Further, the heat pump controller 32 determines the above-described steady-state value TH0 as a saturation temperature THsatu of the coolant, which is obtained from the radiator pressure PCI (the coolant pressure of the radiator 4) + a predetermined offset value. Furthermore, in this case, the heat pump controller 32 also changes the time constant Tau3 depending on the volumetric air volume GA as shown in the Fig. 8 is shown.

[0114] Since also in the dehumidifying and heating mode as described above, the change in the temperature of the air on the leeward side of the radiator 4 varies depending on the flow rate of the air in the air flow duct 3, the time constant Tau in the approximate formula TH = (INTL × TH0 + Tau × THz) / (Tau + INTL) is changed depending on the volumetric air volume Ga, thereby enabling the heating temperature TH to coincide with the actual change in the temperature of the air on the leeward side of the radiator 4.

[0115] Furthermore, also in the dehumidification and cooling mode, the steady-state value TH0 is determined based on the saturation temperature THsatu, which is the average temperature of the radiator, taking into account the subcooling degree SC of the coolant in the radiator, whereby the heating temperature TH can be estimated accordingly. (11 - 7) Calculation of the heating temperature TH in the cooling mode

[0116] Next, when the operation mode is the cooling mode, the heat pump controller 32 proceeds from step S7 to step S15 of the Fig. 7 to determine the above-described time constant Tau as a time constant Tau3. Further, the heat pump controller 32 determines the above-described steady-state value TH0 as the average value of the coolant inlet temperature TClin and the coolant outlet temperature TCI of the radiator 4 + a predetermined offset value. Furthermore, in this case, the heat pump controller 32 also changes the time constant Tau3 depending on the volumetric air volume Ga as shown in the Fig. 8 is shown.

[0117] Since, as described above, the change in temperature of the air on a leeward side of the radiator 4 varies depending on the flow rate of the air in the air flow duct 3 even in the case of the cooling mode, the time constant Tau in the approximate formula TH = (INTL × TH0 + Tau × THz) / (Tau + INTL) is changed depending on the volumetric air volume Ga, thereby enabling the heating temperature TH to coincide with the actual change in temperature of the air on a leeward side of the radiator 4.

[0118] Further, even in the cooling mode, the degree of supercooling is not applied to the coolant in the radiator 4, and therefore, the average temperature of the radiator 4 is determined from the average value of the coolant inlet temperature TClin and the coolant outlet temperature TCI of the radiator 4 and is therefore simply determined as the steady-state value TH0, thereby making it possible to estimate the heating temperature TH accordingly. (11 - 8) Calculation of the heating temperature TH during an operation stop

[0119] Next, when the vehicle air conditioner 1 stops operation (system stop), the heat pump controller 32 proceeds from step S7 to step S8 of the Fig. 7 to determine the above-described time constant Tau as the time constant Tau0. Further, the heat pump controller 32 determines the above-described steady-state value TH0 as the saturation temperature THsatu obtained from the radiator pressure PCI (the coolant pressure of the radiator 4) + a predetermined offset value, or determines the above-described steady-state value TH0 as the average of the coolant inlet temperature TCIin and the coolant outlet temperature TCI of the radiator 4 + a predetermined offset value. Incidentally, even in this case, the heat pump controller does not change the time constant Tau0 even if the above-described volumetric air volume Ga changes, and in this embodiment, the heat pump controller 32 determines the time constant as "10" (the fastest response speed) as shown in the time constant table of the Fig. 8 is shown.

[0120] Therefore, the response speed during an operation stop is set quickly, assuming that the time constant Tau is Tau0, and the steady-state value TH0 is determined based on the saturation temperature THsatu of the coolant obtained from the radiator pressure PCI, or the average value of the coolant inlet temperature TCIin under the coolant outlet temperature TCI of the radiator 4, thereby making it possible to smoothly assume control using the heating temperature TH when the operation is started next time. [Embodiment 2]

[0121] Next, Fig. 10 is a schematic diagram of a vehicle air conditioning system of another embodiment to which the present invention is applied. Incidentally, in this drawing, the components designated by the same reference numerals as in FIG. Fig. 1, the same or a similar function. In the case of the present embodiment, an outlet of the subcooling unit 16 is connected to a check valve 18. An outlet of the check valve 18 is connected to a refrigerant line 13B. Incidentally, the check valve 18 has a side toward the refrigerant line 13B (an internal expansion valve 8) serving as a forward direction.

[0122] Further, a refrigerant line 13E branches off at an outlet side of a radiator 4 to an outdoor expansion valve 6, and this branched refrigerant line (hereinafter referred to as a second bypass line) 13F communicates and connects a refrigerant line 13B on a downstream side of the check valve 18 via a spool valve 22 (for dehumidification). Then, the spool valve 22 is also connected to an output of the heat pump controller 32. Further, the bypass unit 45, which is formed of the bypass line 35, the spool valve 30, and the spool valve 40, is in Fig. 1 of the above-described embodiment is not provided. Since other similar to the Fig. 1, its description is omitted here.

[0123] With the above configuration, the operation of the vehicle air conditioner 1 of this embodiment will be described. In this embodiment, the heat pump controller 32 switches and executes the respective operation modes, including a heating mode, a dehumidifying and heating mode, an internal air circulation mode, a dehumidifying and cooling mode, a cooling mode, and an auxiliary heater single mode (a MAX cooling mode does not exist in this embodiment). Incidentally, since the operation and flow of the coolant when the heating mode, the dehumidifying and cooling mode, and the cooling mode are selected, and the auxiliary heater single mode are similar to those in the above-described embodiment (Embodiment 1), their description will be omitted. However, in the present embodiment (Embodiment 2), it is assumed that the spool valve 22 is closed in the heating mode, the dehumidifying and cooling mode, and the cooling mode. (12) Dehumidification and heating mode of the vehicle air conditioning system 1 in Fig. 10

[0124] On the other hand, when the dehumidification and heating mode is selected, the heat pump controller 32 opens a spool valve 21 (for heating) and closes the spool valve 17 (for cooling) in this embodiment (Embodiment 2). Furthermore, the heat pump controller 32 opens the spool valve 22 (for dehumidification). Then, the heat pump controller 32 operates a compressor 2. An air conditioning controller 20 operates the respective fans 15 and 27, and an air mixing damper 28 substantially has a state where all the air in an air flow passage 3, which is blown out from an indoor fan 27 and flows over a heat absorber 9, is passed through an auxiliary heater 23 and a radiator 4 into a heating heat exchange passage 3A, but also performs air volume adjustment.

[0125] Consequently, a high-temperature and high-pressure gaseous refrigerant discharged from the compressor 2 flows into the radiator 4 from a refrigerant passage 13G. Since the air in the air flow passage 3, which flows into the heater heat exchange passage 3A, 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, the refrigerant in the radiator 4 has the heat removed by the air and is cooled to condense and liquefy.

[0126] The liquefied refrigerant in the radiator 4 flows out of the radiator 4 and then reaches the outdoor expansion valve 6 through the refrigerant line 13E. The refrigerant flowing into the outdoor expansion valve 6 is decompressed therein and then flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 evaporates, and the heat is pumped out by the outside air through the evaporator or the outdoor fan 15. In other words, the refrigerant circuit R functions as a heat pump. Then, the circulation is repeated, in which the low-temperature refrigerant flowing out of the outdoor heat exchanger 7 flows via a refrigerant line 13A, the spool valve 21, and the refrigerant line 13D from a refrigerant line 13C into an accumulator 12, where it undergoes gas-liquid separation, and the gaseous refrigerant is then sucked into the compressor 2.

[0127] Furthermore, a portion of the condensed refrigerant flowing to the refrigerant line 13E through the radiator 4 is dispersed and flows through the spool valve 22 to reach the internal expansion valve 8 from the second bypass line 13F and the refrigerant line 13B through the internal heat exchanger 19. The refrigerant is decompressed by the internal expansion valve 8 and then flows into the heat absorber 9 to evaporate. The water in the air blown out from the indoor fan 27 coagulates to adhere to the heat absorber 9 through a heat absorption operation at this time, and thus the air is cooled and dehumidified.

[0128] Circulation is repeated in which the refrigerant evaporated in the heat absorber 9 is combined with the refrigerant from the refrigerant line 13D at the refrigerant line 13C through the internal heat exchanger 19, and is then sucked into the compressor 2 through the accumulator 12. The air dehumidified in the heat absorber 9 is reheated in the process of passing the radiator 4, and therefore, dehumidification and heating of the vehicle interior are performed.

[0129] The air conditioning controller 20 transmits a target heater temperature TCO (a target radiator outlet temperature TCI) calculated from a target outlet temperature TAO to the heat pump controller 32. The heat pump controller 32 calculates a target radiator pressure PCO (a target radiator pressure PCI) from the target heater temperature TCO, and controls the number of revolutions NC of the compressor 2 based on the target radiator pressure PCO and the refrigerant pressure (a radiator pressure PCI, which is a high pressure of the refrigerant circuit R) of the radiator 4 detected by the radiator pressure sensor 47 to control heating by the radiator 4.Further, the heat pump controller 32 controls a valve position of the outdoor expansion valve 6 based on a temperature Te of the heat absorber 9 detected by a heat absorber temperature sensor 48 and a target value of the heat absorber temperature TEO transmitted from the air conditioning controller 20. (13) Internal recirculation mode of the vehicle air conditioning system 1 of Fig. 10

[0130] Further, in the internal recirculation mode, the heat pump controller 32 completely closes the outdoor expansion valve 6 from a state of the above dehumidification and heating mode (fully open position), and closes the spool valve 21. By closing the outdoor expansion valve 6 and the spool valve 21, the flow of the refrigerant into the outdoor heat exchanger 7 and the outflow of the refrigerant from the outdoor heat exchanger 7 are prevented, and therefore the condensed refrigerant flowing into the refrigerant line 13E through the radiator 4 completely flows into the second bypass line 13F through the spool valve 22. Then, the refrigerant flowing through the second bypass line 13E from the refrigerant line 13B reaches the indoor expansion valve 8 through the internal heat exchanger 19. The refrigerant is decompressed by the indoor expansion valve 8 and then flows into the heat absorber 9 to evaporate.The water in the air blown out from the indoor fan 27 coagulates to adhere in the heat absorber 9 by the heat absorption operation at this time, and therefore the air is cooled and dehumidified.

[0131] A circulation is repeated, in which the refrigerant evaporated in the heat absorber 9 flows into the refrigerant line 13C through the internal heat exchanger 19 and is sucked into the compressor 2 through the accumulator 12. The air dehumidified in the heat absorber 9 is reheated by passing through the radiator 4, thereby performing dehumidification and heating of the vehicle interior. However, in the internal recirculation mode, since the refrigerant circulates between the radiator 4 (heat radiation) and the heat absorber 9 (heat absorption), which is located on an inner side in the air flow channel 3, heat pumping from the outside air is not performed, and heating capability corresponding to the power consumption of the compressor 2 is exhibited.Since the entire amount of the refrigerant flows through the heat absorber 9 having a dehumidifying operation, a dehumidifying capability is high compared with the above-described dehumidifying and heating mode, but the heating capabilities become low.

[0132] The air conditioning controller 20 transmits the target heater temperature TCO (the target radiator outlet temperature TCI) calculated from a target outlet temperature TAO to the heat pump controller 32. The heat pump controller 32 calculates a target radiator pressure PCO (a target radiator pressure PCI) from the transmitted target heater temperature TCO, and controls the number of revolutions NC of the compressor 2 based on the target radiator pressure PCO and the refrigerant pressure (the radiator pressure PCI, which is a high pressure of the refrigerant circuit R) of the radiator 4 detected by the radiator pressure sensor 47, to control heating by the radiator 4. (14) Estimating the heating temperature TH by the operation mode in the embodiment of Fig. 10

[0133] Then, in the present embodiment, a heating temperature TH, that is, a temperature of the air on the leeward side of the radiator 4, is calculated by the approximate formula (II) described above. Then, the heating temperature TH is used for calculating the air volume ratio SW at which the air is passed through the radiator 4 and for switching the respective operation mode in the air conditioning controller 20. However, similarly, in the present embodiment, the heat pump controller 32 calculates the heating temperature TH using an approximate formula that varies depending on the operation mode.

[0134] Incidentally, in the auxiliary heater single mode or when the compressor 2 and the auxiliary heater 23 are stopped, the heating temperature TH is calculated in a manner similar to the above-described (11-1) case. Thus, even at the start of the transition from the dehumidifying and heating mode to the heating mode or during the start-up of the compressor 2, the heating temperature TH is calculated as in the above-described (11-2) case. Furthermore, even in the heating mode, the heating temperature TH is calculated as in the above-described (11-3) case. In addition, even in the dehumidifying and cooling mode, the heating temperature TH is calculated as in the above-described (11-6) case. Furthermore, even in the cooling mode, the heating temperature TH is calculated as in the above-described (11-7) case. (14 - 1) Calculation of heating temperature in dehumidification and heating mode, internal recirculation mode and during operation stop

[0135] In the dehumidification and heating mode and the internal air recirculation mode in the present embodiment, when the vehicle air conditioner 1 stops operating (system stop), the heat pump controller 32 determines the above-described time constant Tau as the time constant Tau0. Further, the heat pump controller 32 determines the above-described steady-state value TH0 as the saturation temperature THsatu of the coolant obtained from the radiator pressure PCI (the coolant pressure of the radiator 4) + a predetermined offset value. Incidentally, even in this case, the heat pump controller 32 does not change the time constant Tau0 even when the above-described volumetric air volume Ga changes, and in this embodiment, the heat pump controller 32 determines the time constant as “10” (the fastest response speed) as shown in the time constant table of the Fig. 8 is shown.

[0136] Therefore, in the dehumidifying and heating mode and the internal air circulation mode, and during operation stop in the present embodiment, the response speed is made fast, assuming that the time constant Tau is equal to Tau0, thereby enabling the heating temperature TH to coincide with an actual change in the temperature of the air on a leeward side of the radiator 4. Furthermore, also in the dehumidifying and heating mode and the internal air circulation mode in this case, the steady-state value TH0 is determined based on the saturation temperature THsatu, which is an average temperature of the radiator 4, taking into account the supercooling degree SC of the coolant in the radiator 4, thereby making it possible to estimate the heating temperature TH accordingly.Further, the same manner is also applied during an operation stop, and therefore, the control can be smoothly resumed using the heating temperature TH when the operation is started next.

[0137] Incidentally, the numerical values and the like shown in the individual embodiments are not limited to these and should be set to appropriate values depending on the device to which they are applied. Furthermore, the auxiliary heater is not limited to the auxiliary heater 23 shown in the embodiments, but may also use a heating medium circulation circuit of a circulating heating medium heated by a heater to heat the air in the air flow passage 3, a heater core of circulating radiator water heated by a motor, etc. Extract from the reference symbols 1 air conditioning system for vehicles 2 compressor 3 Airflow channel 4 Radiators 6 external expansion valve 7 external heat exchanger 8 internal expansion valve 9 heat absorbers 10 HVAC units 11 Control unit 20 air conditioning controllers 23 Auxiliary heater (auxiliary heater) 27 Internal fan (blower fan) 28 air mixing damper 32 heat pump controllers 65 Vehicle communication bus R coolant circuit

Claims

[1] A vehicle air conditioning system (1) comprising: a compressor (2) for compressing a coolant; an air flow duct (3) through which air flows to supply a vehicle interior; a radiator (4) through which the coolant can radiate heat, heating the air supplied to the interior of the vehicle through the air flow duct (3); a heat absorber (9) through which the coolant can absorb heat, wherein the air supplied to the interior of the vehicle through the air flow duct (3) is cooled; and a control unit (11), wherein the control unit (11) is arranged to to switch and execute a variety of operating modes to condition the air in the vehicle interior, wherein the control unit (11) is configured to calculate a heating temperature TH, which is a temperature of the air on a leeward side of the radiator (4), and to use the heating temperature TH in the control and to calculate the heating temperature TH using an approximate formula which varies depending on the set operating mode, wherein the control unit (11) is configured to perform a first-order calculation of a delay of a time constant Tau differently for calculating the heating temperature TH, depending on the set operating mode. [2] The vehicle air conditioning system (1) according to claim 1, wherein the control unit (11) uses the heating temperature TH to calculate an air volume ratio SW at which the air is passed through the radiator (4) and / or to switch the operating modes. [3] The vehicle air conditioner (1) according to claim 1 or 2, wherein the control unit (11) is arranged to change the time constant Tau of the first-order delay according to a volumetric air volume Ga of the air flowing into the air flow channel (3). [4] The vehicle air conditioner (1) according to any one of claims 1 to 3, wherein the control unit (11) is configured to calculate the heating temperature TH based on a steady-state value TH0, which is a value of the heating temperature TH in a steady state, and the time constant Tau of the first-order delay. [5] The vehicle air conditioning system (1) according to claim 4, comprising: an external heat exchanger (7) provided outside the vehicle interior, wherein the control unit (11) has a dehumidification and cooling mode in which the coolant discharged from the compressor (2) flows from the radiator (4) to the external heat exchanger (7), the coolant in the radiator (4) and the external heat exchanger (7) radiates heat, the heat-radiated coolant is decompressed, and the coolant in the heat absorber (9) absorbs heat, and wherein in the dehumidifying and cooling mode, the control unit (11) is adapted to determine the steady-state value TH0 on the basis of a saturation temperature THsatu of the coolant obtained from a coolant pressure PCI of the radiator (4). [6] The vehicle air conditioning system (1) according to claim 4 or 5 comprising: an external heat exchanger (7) which is provided outside the vehicle interior, wherein the control unit (11) has a cooling mode in which the coolant, which is discharged from the compressor (2), flows from the radiator (4) into the external heat exchanger (7), the coolant radiates heat in the external heat exchanger (7), the heat-radiated coolant is decompressed, and the coolant then absorbs heat in the heat absorber (9), and wherein in the cooling mode the control unit (11) is arranged to to determine the stationary value TH0 on the basis of an average value of the coolant temperatures at an inlet and at an outlet of the radiator (4). [7] The vehicle air conditioning system (1) according to one of claims 4 to 6, comprising: a bypass unit (45) that allows the coolant discharged from the compressor (2) to flow directly into the external heat exchanger (7) without flowing to the radiator (4), wherein the control unit (11) has a maximum cooling mode for allowing the coolant discharged from the compressor (2) to flow into the external heat exchanger (7) through the bypass unit (45) and radiate heat therein, decompressing the heat-radiated coolant, and then allowing the coolant to absorb heat in the heat absorber (9), and wherein in the maximum cooling mode, the control unit (11) is configured to determine the steady-state value TH0 based on the average value of the coolant temperatures of the inlet and outlet of the radiator (4). [8] The vehicle air conditioning system (1) according to any one of claims 4 to 7, wherein the control unit (11) has a heating mode for allowing the coolant discharged from the compressor (2) to flow into the radiator (4) and radiate heat therein, decompressing the heat-radiated coolant, and then allowing the coolant to absorb heat in the external heat exchanger (7), wherein in the heating mode, the control unit (11) is configured to correct the saturation temperature THsatu of the coolant, which is obtained from the coolant pressure PCI of the radiator (4), by a predetermined correction value to determine the steady-state value TH0, and wherein the control unit (11) is configured to determine the correction value from a supercooling degree SC of the coolant in the radiator (4) and the volumetric air volume Ga of the air flowing into the air flow channel (3),or the volumetric air volume Ga and an air volume ratio SW with which the air is passed through the radiator (4). [9] The vehicle air conditioning system (1) according to one of claims 4 to 8 comprising: a bypass unit (45) to allow the coolant discharged from the compressor (2) to flow directly into the external heat exchanger (7), without flowing into the radiator (4); and an auxiliary heater (23) for heating the air supplied from the air flow duct (3) into the vehicle interior, wherein the control unit (11) is designed to control a dehumidification and Heating mode to allow the coolant discharged from the compressor (2) to flow into the external heat exchanger (7) through the bypass unit (45) and radiate heat therein, to decompress the heat-radiated coolant, then to allow the coolant to absorb heat in the heat absorber (9), and to allow the auxiliary heater (23) to generate heat, and wherein in the dehumidification and heating mode, the control unit (11) is adapted to determine the steady-state value TH0 based on a temperature Tptc of the auxiliary heater (23). [10] The vehicle air conditioner (1) according to any one of claims 4 to 8, wherein the control unit (11) has a dehumidifying and heating mode for letting the refrigerant discharged from the compressor (2) radiate heat in the radiator (4), decompressing the heat-radiated refrigerant, and then letting the refrigerant absorb heat only in the heat absorber (9), or in the heat absorber (9) and the external heat exchanger (7), and wherein in the dehumidifying and heating mode, the control unit (11) is arranged to determine the steady-state value TH0 based on the saturation temperature THsatu of the refrigerant obtained from the refrigerant pressure PCI of the radiator (4). [11] The vehicle air conditioning system (1) according to any one of claims 4 to 10, wherein the control unit (11) is arranged to determine the steady-state value TH0 on the basis of the saturation temperature THsatu of the coolant obtained from the coolant pressure PCI of the radiator (4) or the average value of the coolant temperatures of the inlet and the outlet of the radiator (4) during an operation stop.

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