Vehicle air conditioning system

Abstract

Vehicle air conditioning unit (1) with: a compressor (2) that compresses a coolant; an airflow channel (3) through which air flows to supply a vehicle interior, a heating element (4) which causes the coolant to radiate heat in order to heat the air which is supplied from the airflow duct (3) into the vehicle interior; a heat absorber (9) which causes the coolant to absorb heat in order to cool the air which is supplied from the airflow duct (3) into the vehicle interior; an external heat exchanger (7) located outside the vehicle interior to cause the coolant to radiate or absorb heat; and a control device (32), wherein the control device (32) is configured to perform at least one heating mode in which the coolant discharged from the compressor (2) radiates heat in the radiator (4) and the coolant from which heat has been radiated is expanded and then absorbs heat in the external heat exchanger (7), wherein the vehicle air conditioning device (1) comprises the following: an auxiliary heating device (23) for heating the air which is to be supplied from the airflow duct (3) into the vehicle interior, wherein the control device (32) is configured to calculate a required coolant evaporation temperature (TXObaseQtgt) in non-icing conditions, which is a coolant evaporation temperature of the external heat exchanger (7) when a required heating capacity (Qtgt) is achieved as a heating capacity required for the radiator (4) in non-icing conditions of the external heat exchanger (7), and the control device (32) is further configured to control the heating by the radiator (4) and the heating by the auxiliary heating device (23) on the basis of the required coolant evaporation temperature (TXObaseQtgt) in non-icing conditions and a frost point (Tfrost) in order to achieve the required heating capacity (Qtgt) without causing ice formation on the external heat exchanger (7), wherein the control device (32) is further configured toto calculate the required coolant evaporation temperature (TXObaseQtgt) in non-icing conditions based on an outside air temperature and the required heating capacity (Qtgt).

Description

Technical area

[0001] The present invention relates to an air conditioning device of a heat pump system that conditions air in a vehicle interior, and more particularly, it relates to an air conditioning device applicable to a hybrid vehicle or an electric vehicle. State of the art

[0002] Due to current environmental problems in recent years, hybrid vehicles and electric vehicles have become widespread. Furthermore, as an air conditioning device applicable to such a vehicle, an air conditioning device has been developed that includes a compressor for compressing and discharging a refrigerant, a radiator (a condenser) arranged on a vehicle interior for causing the refrigerant to radiate heat, a heat absorber (an evaporator) arranged on the vehicle interior for causing the refrigerant to absorb heat, and an exterior heat exchanger arranged outside the vehicle interior for causing the refrigerant to radiate or absorb heat, and that changes and executes various modes, such as a heating mode in which the refrigerant discharged from the compressor radiates heat in the radiator and the refrigerant,from which heat was radiated in this radiator, absorbs heat in the outdoor heat exchanger, a dehumidification mode in which the coolant discharged from the compressor radiates heat in the radiator and the coolant from which heat was radiated in the radiator absorbs heat in the heat absorber, and a cooling mode in which the coolant discharged from the compressor radiates heat in the outdoor heat exchanger and absorbs heat in the heat absorber (such as JP 3 985 384 B2).

[0003] JP 3 985 384 B2 discloses a vehicle air conditioning device according to the previously described prior art. Further relevant vehicle air conditioning devices from the prior art are disclosed in patent document US 2011 / 0 016 896 A1 and patent document DE 11 2013 005 737 T5. Summary of the inventionProblems to be solved by the invention

[0004] In the heating mode described above, an outdoor heat exchanger serves as an evaporator of a refrigerant. Therefore, when the heating mode is executed by starting a vehicle air conditioning device, water in the outside air adheres to the outdoor heat exchanger as frost, and this frost grows depending on the conditions of outside air temperature and humidity. When frost formation occurs on the outdoor heat exchanger in the heating mode, the frost becomes an insulating material. Therefore, a heat exchange function with the outside air deteriorates significantly, heat cannot be absorbed from the outside air, and thus there is a problem that a required heating capacity cannot be obtained.

[0005] The present invention has been developed to solve such conventional technical problems, and its object is to provide comfortable heating of a vehicle interior by preventing or suppressing frost formation on an outdoor heat exchanger in an air conditioning device of a so-called heat pump system. Means to solve the problems

[0006] A vehicle air conditioning device of the present invention includes a compressor that compresses a refrigerant, an air flow passage through which air to be supplied to a vehicle interior flows, a heater core that causes the refrigerant to radiate heat to heat the air to be supplied from the air flow passage into the vehicle interior, a heat absorber that causes the refrigerant to absorb heat to cool the air to be supplied from the air flow passage into the vehicle interior, an outdoor heat exchanger arranged outside the vehicle interior for causing the refrigerant to radiate or absorb heat, and a control device, this control device being configured to execute at least a heating mode in which the refrigerant discharged from the compressor radiates heat in the heater core and the refrigerant from which heat has been radiatedis expanded and then absorbs heat in the outdoor heat exchanger, wherein the vehicle air conditioning device has an auxiliary heating device for heating the air to be supplied from the air flow duct into the vehicle interior, and it is characterized in that the control device is configured to calculate a required non-icing coolant evaporation temperature (TXObaseQtgt), which is a coolant evaporation temperature of the outdoor heat exchanger when a required heating capacity (Qtgt) is realized as a heating capacity required for the heater core when the outdoor heat exchanger is not icing, and the control device is configured to control heating by the heater core and heating by the auxiliary heating device based on this required non-icing coolant evaporation temperature (TXObaseQtgt) and a frost point Tfrost to achieve the required heating capacity (Qtgt).without causing ice formation on the exterior heat exchanger. Furthermore, the vehicle air conditioning device according to the invention is characterized in that the control device is configured to calculate the required refrigerant evaporation temperature (TXObaseQtgt) in non-icing conditions based on the outside air temperature and the required heating capacity (Qtgt).

[0007] The vehicle air conditioning device of the invention according to claim 2 is characterized in that, in the invention described above, the control device is configured to calculate a predicted value of the maximum heating capacity without frost (QmaxNfst), which is a target value of a maximum heating capacity to be generated by the heater core in a region where the outdoor heat exchanger is not frosted, and the control device is configured to define a target heating capacity (TGQhp) of the heater core as the predicted value of the maximum heating capacity without frost (QmaxNfst), and to compensate for a shortfall of the predicted value of the maximum heating capacity without frost (QmaxNfst) to the required heating capacity (Qtgt) by heating by the auxiliary heater when the required refrigerant evaporation temperature (TXObaseQtgt) in non-frost is lower than the frost point (Tfrost) or a temperature close to the frost point.

[0008] The vehicle air conditioning device of the invention according to claim 3 is characterized in that in the invention described above, the control device is configured to calculate the predicted value of the maximum heating capacity (QmaxNfst) without frosting based on the frost point (Tfrost) or the temperature near the frost point and an outside air temperature.

[0009] The vehicle air conditioning device of the invention according to claim 4 is characterized in that in the respective inventions described above, the control means is configured to define the target heating capacity (TGQhp) of the heater core as the required heating capacity (Qtgt) and to stop heating by the auxiliary heater when the required refrigerant evaporation temperature (TXObaseQtgt) in non-icing is the frost point (Tfrost) or a temperature close to the frost point or higher.

[0010] The vehicle air conditioning device of the invention according to claim 5 is characterized in that the control means is configured to execute the control of the respective inventions described above immediately after the start.

[0011] The vehicle air conditioning device of the invention according to claim 6 is characterized in that, in the respective inventions described above, the control device includes frost formation state estimation means for estimating a state of frost formation on the outdoor heat exchanger, and the control device is configured to execute heating by the auxiliary heating means when frost formation occurs on the outdoor heat exchanger or when frost formation on the outdoor heat exchanger is predicted based on the estimation by this frost formation state estimation means in a case where it is not immediately after the start.

[0012] The vehicle air conditioning device of the invention according to claim 7 is characterized in that, in the invention described above, the control device is configured to calculate a target heating capacity (TGQech) of the auxiliary heater for inhibiting or preventing frost formation on the outdoor heat exchanger based on a degree of frost formation on the outdoor heat exchanger, and obtain a value of the target heating capacity (TGQhp) of the heater core by subtracting the target heating capacity (TGQech) of the auxiliary heater from the required heating capacity (Qtgt).

[0013] The vehicle air conditioning device of the invention according to claim 8 is characterized in that in the invention described above, the control device is configured to stop an operation of the compressor when the target heating capacity (TGQhp) of the heater core is smaller than a predetermined value.

[0014] The vehicle air conditioning device of the invention according to claim 9 is characterized in that in the inventions according to claim 6 to claim 8, the control means is configured to decrease the heating by the auxiliary heating means gradually or in stages and finally stop the heating when it estimates that the outdoor heat exchanger is not frosted based on the estimation of the frost formation state estimation means.

[0015] The vehicle air conditioning device of the invention according to claim 10 is characterized in that in the inventions according to claim 6 to claim 9, the control device is configured to estimate the frost formation state or the degree of frost formation on the outdoor heat exchanger based on the frost point (Tfrost) and a refrigerant evaporation temperature (TXO) of the outdoor heat exchanger.

[0016] The vehicle air conditioning device of the invention according to claim 11 is characterized in that, in the respective inventions described above, the auxiliary heating means is constituted by a heating medium circulation circuit having a heating medium / air heat exchanger for heating the air to be supplied from the air flow passage into the vehicle interior, an electric heater, and a circulation means, and configured to circulate a heating medium heated by the electric heater through the heating medium / air heat exchanger through the circulation means. Advantageous effect of the invention

[0017] According to the present invention, in a vehicle air conditioning device comprising a compressor that compresses a refrigerant, an air flow duct through which air to be supplied to a vehicle interior flows, a heater core that causes the refrigerant to radiate heat to heat the air to be supplied from the air flow duct into the vehicle interior, a heat absorber that causes the refrigerant to absorb heat to cool the air to be supplied from the air flow duct into the vehicle interior, an outdoor heat exchanger arranged outside the vehicle interior for causing the refrigerant to radiate or absorb heat, and a control device, this control device being configured to execute at least a heating mode in which the refrigerant discharged from the compressor radiates heat in the heater core and the refrigerant from which heat has been radiatedis expanded and then absorbs heat in the outdoor heat exchanger, an auxiliary heater is arranged for heating the air to be supplied from the air flow duct into the vehicle interior, and the control device calculates a required non-icing coolant evaporation temperature (TXObaseQtgt), which is a coolant evaporation temperature of the outdoor heat exchanger when a required heating capacity (Qtgt) is realized as a heating capacity required for the heater core when the outdoor heat exchanger is not icing, and the control device controls heating by the heater core and heating by the auxiliary heater based on this required non-icing coolant evaporation temperature (TXObaseQtgt) and a frost point (Tfrost) to achieve the required heating capacity (Qtgt),without causing frost formation on the exterior heat exchanger. Therefore, the required heating capacity (Qtgt) can be achieved through coordinated heating of the radiator and the auxiliary heater without causing frost formation on the exterior heat exchanger, based on the frost point at which frost forms on the exterior heat exchanger, and comfortable heating of the vehicle interior can be achieved.

[0018] In this case, the controller calculates the required refrigerant evaporation temperature (TXObaseQtgt) at non-icing based on an outside air temperature and the required heating capacity (Qtgt), so that it is possible to accurately estimate the required refrigerant evaporation temperature (TXObaseQtgt) at non-icing that realizes the required heating capacity (Qtgt) at non-icing of the outdoor heat exchanger, and it is possible to effectively prevent frost formation on the outdoor heat exchanger.

[0019] As in the invention according to claim 2, the control device additionally calculates a predicted value of a maximum heating capacity without frosting (QmaxNfst), which is a target value of the maximum heating capacity to be generated by the heater in a region where the outdoor heat exchanger is not frosted, and the control device defines a target heating capacity (TGQhp) of the heater as the predicted value of the maximum heating capacity without frosting (QmaxNfst), and compensates for a deficiency of the predicted value of the maximum heating capacity without frosting (QmaxNfst) to the required heating capacity (Qtgt) by heating by the auxiliary heater when the required refrigerant evaporation temperature (TXObaseQtgt) in non-frosting is lower than the frost point (Tfrost) or a temperature close to the frost point.As in the invention according to claim 4, the control device defines the target heating capacity (TGQhp) of the heater core as the required heating capacity (Qtgt), and stops heating by the auxiliary heater when the required coolant evaporation temperature (TXObaseQtgt) in non-icing conditions is the frost point (Tfrost) or a temperature after the frost point or higher. In this case, it is possible to minimize deterioration of efficiency due to heating by the auxiliary heater. Consequently, it is possible to effectively prevent the disadvantage of a reduced cruising range, particularly in an electric vehicle.

[0020] As in the invention according to claim 3, the control device additionally calculates the predicted value of the maximum heating capacity (QmaxNfst) without icing based on the frost point (Tfrost) or the temperature near the frost point and an outside air temperature, so that it is possible to accurately estimate the predicted value of the maximum heating capacity (QmaxNfst) without icing at which the outdoor heat exchanger is not icy and to more effectively prevent icing on the outdoor heat exchanger.

[0021] Furthermore, as in the invention according to claim 5, the control device executes the above-described control immediately after startup, and thus it is possible to prevent the disadvantage that frost formation on the outdoor heat exchanger begins due to starting from a stopped state, that is, from a state where the outdoor heat exchanger is not yet frosted, and it is possible to suppress the growth of frost formation due to subsequent travel as much as possible. In addition, compensation by the auxiliary heater by estimating the required refrigerant evaporation temperature (TXObaseQtgt) under non-frosting is performed only immediately after startup, and thus it is also possible to achieve a reduction in power consumption.

[0022] As with the invention according to claim 6, the control device additionally includes frost formation state estimation means for estimating a state of frost formation on the outdoor heat exchanger, and the control device performs heating by the auxiliary heating means when frost formation occurs on the outdoor heat exchanger or when frost formation on the outdoor heat exchanger is predicted, based on the estimation by this frost formation state estimation means in a case where it is not immediately after startup. In this case, it is possible to provide heating capability in the vehicle interior while effectively preventing or suppressing frost formation on the outdoor heat exchanger during travel after startup.

[0023] As in the invention according to claim 7, the control device further calculates, based on a degree of frost formation on the outdoor heat exchanger, a target heating capacity (TGQech) of the auxiliary heater to inhibit or prevent frost formation on the outdoor heat exchanger, and obtains a value of the target heating capacity (TGQhp) of the heater core by subtracting the target heating capacity (TGQech) of the auxiliary heater from the required heating capacity (Qtgt), so that heating by the auxiliary heater can be accurately controlled while inhibiting or preventing frost formation on the outdoor heat exchanger, and comfortable heating of the vehicle interior can be realized.

[0024] In this case too, it is possible to minimize the deterioration of efficiency due to heating by the auxiliary heater, and thus it is also possible to effectively prevent the reduction of the driving range of the electric vehicle.

[0025] In this case, as in the invention according to claim 8, the control device stops an operation of the compressor when the target heating capacity (TGQhp) of the heater is smaller than a predetermined value, and thus the deterioration of the efficiency in a situation where the heating of the heater is excessively low can be avoided in advance.

[0026] It should be noted that, as in the invention according to claim 9, the control means decreases the heating by the auxiliary heater gradually or in stages and finally stops the heating when it is estimated that the outdoor heat exchanger is not frosted based on the estimation by the frost formation state estimation means, and in this case, it is possible to suppress a rapid change in a temperature of the air to be blown out into the vehicle interior, and it is also possible to prevent or suppress that disadvantage that the outdoor heat exchanger is in transition to frosting according to the rapid increase in the heating capacity of the heater core.

[0027] Specifically, as in the invention according to claim 10, the control device estimates the frost formation state or degree of frost formation on the outdoor heat exchanger based on the frost point (Tfrost) and a refrigerant evaporation temperature (TXO) of the outdoor heat exchanger. In this case, it is possible to perform the above-described control by accurately determining the frost formation on the outdoor heat exchanger. Consequently, it is possible to accurately control heating by the auxiliary heater and prevent an increase in power consumption.

[0028] As in the invention according to claim 11, the auxiliary heating device described above is further constituted by a heating medium circulation circuit including a heating medium / air heat exchanger for heating the air to be supplied from the air flow passage into the vehicle interior, an electric heater, and a circulation device, and circulates a heating medium heated by the electric heater through the heating medium / air heat exchanger through the circulation device, and thus it is possible to realize electrically safe heating of the vehicle interior. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a structural view of a vehicle air conditioning device of an embodiment to which the present invention is applied; Fig. 2 shows a block diagram of an electrical circuit of a control device of the vehicle air conditioning device of Fig. 1; Fig. 3 shows an enlarged view of an air flow channel section of the Fig. 1; Fig. Fig. 4 is a flowchart for explaining an operation of the control device of the Fig. 2; Fig. Figure 5 shows a graph of a relationship between a predicted value of a maximum heating capacity without icing of a radiator using an outdoor heat exchanger of the Fig. 1 is not icy, and an outside air temperature; Fig. Fig. 6 is a diagram for explaining an operation of the control device of the Fig. 2; Fig. Fig. 7 is a flowchart for explaining an operation of another embodiment of the control device of the Fig. 2; Fig. Fig. 8 is a flowchart for explaining an operation of another embodiment of the control device of the Fig. 2; Fig. 9 is a structural view of a vehicle air conditioning device of another embodiment to which the present invention is applied; Fig. 10 is a structural view of a vehicle air conditioning device of another embodiment to which the present invention is applied; Fig. 11 is a structural view of a vehicle air conditioning device of another embodiment to which the present invention is applied; Fig. 12 is a structural view of a vehicle air conditioning device of another embodiment to which the present invention is applied; Fig. 13 is a structural view of a vehicle air conditioning device of another embodiment to which the present invention is applied; Fig. 14 is a structural view of a vehicle air conditioning device of another embodiment to which the present invention is applied; and Fig. 15 is a structural view of a vehicle air conditioning device of another embodiment to which the present invention is applied. EMBODIMENT OF THE INVENTION

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0030] The Fig. 1 shows a structural view of a vehicle air conditioning device 1 of an embodiment of the present invention. A vehicle of the embodiment to which the present invention is applied is an electric vehicle (EV) in which no engine (internal combustion engine) is mounted, and it travels by driving an electric motor by running by power charged in a battery (not shown), and the vehicle air conditioning device 1 of the present invention is driven by the power of the battery. Namely, in the electric vehicle in which heating cannot be performed by waste heat of the engine, the vehicle air conditioning device 1 of the embodiment performs heating by a heat pump operation using a refrigerant cycle, and further selectively performs various operation modes of dehumidification and heating, cooling and dehumidification, cooling, and the like.

[0031] It should be noted that the vehicle is not limited to the electric vehicle, and the present invention is also effective for a so-called hybrid vehicle in which the engine is used together with the electric motor for traveling, and needless to say, it is further applicable to a general vehicle traveling by the engine.

[0032] The vehicle air conditioning device 1 of the embodiment performs air conditioning (heating, cooling, dehumidification, and ventilation) in the electric vehicle. An electric compressor 2 that compresses a refrigerant; a heater core 4 disposed in an air flow passage 3 of an HVAC unit 10 through which air passes and circulates in the vehicle interior, causing the high-temperature and high-pressure refrigerant discharged from the compressor 2 to flow into the interior through a refrigerant pipe 13G and radiate heat in the vehicle interior; an outdoor expansion valve 6 formed by an electric valve that relaxes and expands the refrigerant during heating; and an outdoor heat exchanger 7 that performs heat exchange between the refrigerant and the outside air.to serve as the radiator during cooling and to serve as an evaporator during heating, an indoor expansion valve 8 formed by an electric valve that relaxes and expands the coolant, a heat absorber 9 arranged in the air flow channel 3 to cause the coolant to absorb heat from the interior and exterior of the vehicle during cooling and during dehumidification, an evaporation capacity control valve 11 that regulates evaporation capacity in the heat absorber 9, an accumulator 12, and the like, so that a coolant circuit R is formed. Note that an outdoor fan 15 is arranged in the outdoor heat exchanger 7. The outdoor fan 15 forcibly drives the outside air through the outdoor heat exchanger 7 and causes heat exchange between the outside air and the coolant, whereby the outside air also passes through the outdoor heat exchanger 7.when the vehicle is stopped (i.e. a speed VSP is 0 km / h).

[0033] In addition, the outdoor heat exchanger 7 has a receiving drying section 14 and a subcooling section 16 sequentially on a coolant downstream side. A coolant pipe 13A extending from the outdoor heat exchanger 7 is connected to the receiving drying section 14 via a solenoid valve (an opening / closing valve) 17 that is opened during cooling, and an outlet of the subcooling section 16 is connected to the indoor expansion valve 8 via a check valve 18. Note that the receiving drying section 14 and the subcooling section 16 structurally constitute a part of the outdoor heat exchanger 7, and a side of the check valve 18 toward the indoor expansion valve 8 is a forward direction.

[0034] In addition, a refrigerant pipe 13B is arranged between the check valve 18 and the indoor expansion valve 8, which has a heat exchange relationship with a refrigerant pipe 13C extending from the evaporation capability control valve 11 positioned at an outlet side of the heat absorber 9, and both pipes form an indoor heat exchanger 19. Consequently, the refrigerant flowing into the indoor expansion valve 8 through the refrigerant pipe 13B is cooled (subcooled) by the low-temperature refrigerant flowing out of the heat absorber 9 through the evaporation capability control valve 11.

[0035] In addition, the coolant pipe 13A extending from the outdoor heat exchanger 7 is branched, and this branched coolant pipe 13D communicates with the coolant pipe 13C on the downstream side of the indoor heat exchanger 19 via a solenoid valve (an opening / closing valve) 21 that is opened during heating. Furthermore, a coolant pipe 13E is branched on an outlet side of the radiator 4 before the outdoor expansion valve 6, and this branched coolant pipe 13F communicates with the coolant pipe 13B on the downstream side of the check valve 18 via a solenoid valve (an opening / closing valve) 22 that is opened during dehumidification.

[0036] In addition, a bypass pipe 13J is connected in parallel to the outdoor expansion valve 6, and a solenoid valve (an opening / closing valve) 20 is arranged in the bypass pipe 13J, which is opened in the cooling mode and allows the refrigerant to flow and bypass the outdoor expansion valve 6. Note that a pipe 13I is arranged between the outdoor expansion valve 6 and the solenoid valve 20 and the outdoor heat exchanger 7.

[0037] In addition, various suction ports such as an outside air suction port and an inside air suction port are formed in the air flow channel 3 on the air upstream side of the heat absorber 9 (through a suction port in the Fig. 1), and a suction change damper 26 is arranged in the suction port 25 to change the air to be introduced into the air flow duct 3 into inside air, which is air in the vehicle interior (an inside air circulation mode), and outside air, which is air outside the vehicle interior (an outside air introduction mode). Furthermore, an inside blower (blower fan) 27 is arranged on an airstream side of the suction change damper 26 to supply the introduced inside air or outside air to the air flow duct 3.

[0038] In addition, the reference number 23 in the Fig. 1 shows a heating medium circulation circuit as an auxiliary heating device arranged in the vehicle air conditioning device 1 of the embodiment. The heating medium circulation circuit 23 includes a circulation pump 30 constituting a circulation device, an electric heating medium heater (shown by ECH in the drawing) 35, and a heating medium-air heat exchanger 40 arranged in the air flow passage 3 on the downstream side of the heater core 4 to the air flow in the air flow passage 3. These components are sequentially connected by a heating medium pipe 23A in a ring-like manner. Note that, as the heating medium to be circulated in the heating medium circulation circuit 23, for example, water, a coolant such as HFO-1234YF, a refrigerant, or the like is used.

[0039] Furthermore, when the circulation pump 30 is operated and the electric heating medium heater 35 is energized to generate heat, the heating medium heated by the electric heating medium heater 35 is circulated through the heating medium-to-air heat exchanger 40. Namely, the heating medium-to-air heat exchanger 40 of the heating medium circulation circuit 23 is a so-called heater core and supplements the heating in the vehicle interior. In this way, the heating medium circulation circuit 23 is utilized, and therefore, the electrical safety of a passenger can be improved.

[0040] In the air flow duct 3 on the air upstream side of the radiator 4, an air mixing damper 28 is additionally arranged to regulate a flow rate of the inside air or the outside air through the radiator 4. Furthermore, in the air flow duct 3 on the air downstream side of the radiator 4, an outlet for the footwell, the ventilation or a de-icer (through an outlet 29 in the Fig. 1), and an outlet change damper 31 is arranged in the outlet 29 to perform change control for blowing the air from the corresponding outlet mentioned above.

[0041] Next, reference numeral 32 in the Fig. 2, a control unit (ECU) as a control device formed by a microcomputer, and an input of the control unit 32 is connected to respective outputs from an outside air temperature sensor 33 that detects an outside air temperature of the vehicle, an outside air humidity sensor 34 that detects an outside air humidity of the vehicle, an HVAC suction temperature sensor 36 that detects a temperature of the air to be sucked from the suction port 25 to the air flow duct 3, an inside air temperature sensor 37 that detects a temperature of the air in the vehicle interior (the inside air), an inside air humidity sensor 38 that detects a humidity of the air in the vehicle interior, an inside air CO2 concentration sensor 39 that detects a carbon dioxide concentration in the vehicle interior, and an outlet temperature sensor 41 that detects a temperature of the air blown out of the outlet 29 into the vehicle interior.an outlet pressure sensor 42 that detects a pressure of the refrigerant discharged from the compressor 2, an outlet temperature sensor 43 that detects a temperature of the refrigerant discharged from the compressor 2, a suction pressure sensor 44 that detects a refrigerant suction pressure of the compressor 2, a radiator temperature sensor 46 that detects a temperature of the radiator 4 (the temperature of the air passing through the radiator 4 or the temperature of the radiator 4 itself), a radiator pressure sensor 47 that detects a coolant temperature of the radiator 4 (the pressure in the radiator 4 or the pressure of the coolant that has just flowed out of the radiator 4), a heat absorber temperature sensor 48 that detects a temperature of the heat absorber 9 (the temperature of the air that has passed through the heat absorber 9 or the temperature of the heat absorber 9 itself), a heat absorber pressure sensor 49,which detects a coolant pressure of the heat absorber 9 (the pressure in the heat absorber 9 or the pressure of the coolant that has just flowed out of the heat absorber 9), a solar irradiation sensor 51 such as a photosensor system for detecting an amount of solar irradiation in the vehicle, a speed sensor 52 for detecting a moving speed of the vehicle (a speed), an air conditioning operating section 53 for setting the change of the predetermined temperature or the operation mode, an outdoor heat exchanger temperature sensor 54 that detects a temperature of the outdoor heat exchanger 7 (the temperature of the coolant that has just flowed out of the outdoor heat exchanger 7 or the temperature of the outdoor heat exchanger 7 itself), and an outdoor heat exchanger pressure sensor 56 that detects the coolant pressure of the outdoor heat exchanger 7 (the pressure of the coolant in the outdoor heat exchanger 7 or the coolant,which has just flowed out of the outdoor heat exchanger 7).

[0042] In addition, the input of the control device 32 is further connected to various outputs from an electric heating medium heater temperature sensor 50 that detects a temperature of the electric heating medium heater 35 of the heating medium circulation circuit 23 (the temperature of the heating medium immediately after being heated by the electric heating medium heater 35 or a temperature of an unillustrated electric heater itself installed in the electric heating medium heater 35), and a heating medium / air heat exchanger temperature sensor 55 that detects a temperature of the heating medium / air heat exchanger 40 (the temperature of the air that has passed through the heating medium / air heat exchanger 40 or the temperature of the heating medium / air heat exchanger 40 itself).

[0043] On the other hand, an output of the control device 32 is connected to the compressor 2, the outdoor blower 15, the indoor blower (the blower fan) 27, the suction change damper 26, the air mixing damper 28, the discharge change damper 31, the outdoor expansion valve 6, the indoor expansion valve 8, the various solenoid valves 22, 17, 21, and 20, the circulation pump 30, the electric heating medium heater 35, and the evaporative capability control valve 11. Furthermore, the control device 32 controls these components based on the outputs from the various sensors and the setting input by the air conditioning operating section 53.

[0044] Next, an operation of the vehicle air conditioning device 1 of the embodiment having the above-described structure will be described. In the embodiment, the control device 32 changes and executes various roughly classified operation modes, such as a heating mode, a dehumidifying and heating mode, an internal cycle mode, a dehumidifying and cooling mode, and a cooling mode. First, the flow of the refrigerant in each operation mode will be described. (1) Flow of coolant in heating mode

[0045] When the heating mode is selected by the control device 32 or by manual operation on the air conditioning operating section 53, the control device 32 opens the solenoid valve 21 and closes the solenoid valve 17, the solenoid valve 22, and the solenoid valve 20. Furthermore, the compressor 2 and the respective fans 15 and 27 are operated, and the air mixing damper 28 is in a state where the air blown out of the indoor fan 27 passes through the heater core 4 and the heating medium-air heat exchanger 40. Consequently, the high-temperature and high-pressure refrigerant gas discharged from the compressor 2 flows into the heater core 4.The air in the air flow channel 3 passes through the radiator 4, and thus the air in the air flow channel 3 is heated by the high-temperature coolant in the radiator 4, whereas the coolant in the radiator 4 has the heat absorbed by the air and is cooled to condense and liquefy.

[0046] The coolant liquefied in the radiator 4 flows out of the radiator 4 and then flows through the coolant pipe 13E to reach the outdoor expansion valve 6. Note that an operation and function of the heating medium circulation circuit 23 will be described later. The coolant flowing into the outdoor expansion valve 6 is expanded and then flows into the outdoor heat exchanger 7. The coolant flowing into the outdoor heat exchanger 7 is evaporated, and the heat is pumped out by the passing outside air by the flow or by the outdoor fan 15. Namely, the coolant circuit R becomes a heat pump (shown by HP in the drawing), and the outdoor heat exchanger 7 serves as an evaporator of the coolant.Furthermore, the low-temperature coolant flowing out of the exterior heat exchanger 7 flows through the coolant pipe 13D and the solenoid valve 21 to flow from the coolant pipe 13C into the accumulator 12, where gas-liquid separation is performed. Then, the gaseous coolant is sucked into the compressor 2, repeating this circulation. The air heated in the heater core 4 is blown out from the outlet 29 through the heating medium-air heat exchanger 40, thus heating the vehicle interior.

[0047] The control device 32 controls a rotation speed of the compressor 2 based on a high pressure of the refrigerant circuit R detected by the outlet pressure sensor 42 or the radiator pressure sensor 47, and also controls a valve position of the outdoor expansion valve 6 based on the temperature of the radiator 4 detected by the radiator temperature sensor 46 and the refrigerant pressure of the radiator 4 detected by the radiator pressure sensor 47, and controls a subcooling degree of the refrigerant in the outlet of the radiator 4. (2) Flow of refrigerant in dehumidification and heating mode

[0048] Next, in the dehumidification and heating mode, the control device 32 opens the solenoid valve 22 in the above-described heating mode state. Consequently, part of the condensed refrigerant flowing through the radiator 4 and the refrigerant pipe 13E is dispersed, and it flows through the solenoid valve 22 to flow out of the refrigerant pipes 13F and 13B through the indoor heat exchanger 19, thereby reaching the indoor expansion valve 8. The refrigerant is expanded in the indoor expansion valve 8 and then flows into the heat absorber 9 to evaporate. Water in the air blown out from the indoor fan 27 coagulates to adhere to the heat absorber 9 by a heat absorption operation during this period, and thus the air is cooled and dehumidified.

[0049] The refrigerant evaporated in the heat absorber 9 flows through the evaporation capacity control valve 11 and the interior heat exchanger 19 to mix with the refrigerant from the refrigerant pipe 13D in the refrigerant pipe 13C, and then flows through the accumulator 12 to be drawn into the compressor 2, repeating this circulation. The air dehumidified in the heat absorber 9 is reheated by passing through the heater core 4, thus effecting dehumidification and heating of the vehicle interior. The control device 32 controls the rotation speed of the compressor 2 based on the high pressure of the refrigerant circuit R detected by the outlet pressure sensor 42 or the radiator pressure sensor 47, and also controls the valve position of the outdoor expansion valve 6 based on the temperature of the heat absorber 9 detected by the heat absorber temperature sensor 48. (3) Flow of coolant in internal cycle mode

[0050] Next, in the internal cycle mode, the control device 32 interrupts the outdoor expansion valve 6 in the above-described state of the dehumidifying and heating mode (a interruption position), and also closes the solenoid valve 21. The outdoor expansion valve 6 and the solenoid valve 21 are closed, thereby hindering the inflow of the refrigerant into the outdoor heat exchanger 7 and the outflow of the refrigerant from the outdoor heat exchanger 7, and thus all the condensed refrigerant flowing through the radiator 4 and the refrigerant pipe 13E flows through the solenoid valve 22 to the refrigerant pipe 13F. Further, the refrigerant flowing through the refrigerant pipe 13F flows from the refrigerant pipe 13B through the indoor heat exchanger 19 to reach the indoor expansion valve 8. The coolant is expanded in the internal 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 by the heat absorption operation in this period, and thus the air is cooled and dehumidified.

[0051] The refrigerant evaporated in the heat absorber 9 flows through the evaporation capacity control valve 11, the indoor heat exchanger 19, the refrigerant pipe 13C, and the accumulator 12 to be sucked into the compressor 2, and this circulation is repeated. The air dehumidified in the heat absorber 9 is reheated in the process of passing through the heater core 4, thus achieving dehumidification and heating of the vehicle interior. However, in this internal cycle mode, the refrigerant circulates between the heater core 4 (heat radiation) and the heat absorber 9 (heat absorption) located in the air flow passage 3 on an interior side, and thus, heat is not pumped out from the outside air, but a heating capacity for consumed power of the compressor 2 is utilized.The entire amount of the refrigerant flows through the heat absorber 9, which performs a dehumidifying operation, and thus a dehumidifying capacity is high compared with the dehumidifying and heating mode described above, but the heating capacity is reduced.

[0052] The control device 32 controls the rotational speed of the compressor 2 based on the temperature of the heat absorber 9 or the above-described high pressure of the refrigerant circuit R. At this time, the control device 32 selects a smaller compressor target rotational speed from compressor target rotational speeds obtained by calculations from the temperature of the heat absorber 9 or the high pressure to control the compressor 2. (4) Flow of refrigerant in dehumidification and cooling mode

[0053] Next, in the dehumidification and cooling mode, the control device 32 opens the solenoid valve 17, and closes the solenoid valve 21, the solenoid valve 22, and the solenoid valve 20. In addition, the compressor 2 and the respective fans 15 and 27 are operated, and the air mixing damper 28 has the state where the air blown out from the indoor fan 27 passes through the radiator 4 and the heating medium / air heat exchanger 40. Consequently, the high-temperature and high-pressure refrigerant gas discharged from the compressor 2 flows into the heater core 4. Through the heater core 4, the air in the air flow channel 3 passes, and thus the air in the air flow channel 3 is heated by the high-temperature refrigerant in the heater core 4, whereas the refrigerant in the heater core 4 has the heat absorbed by the air and is cooled to condense and liquefy.

[0054] The coolant flowing out of the radiator 4 flows through the coolant pipe 13E to reach the outdoor expansion valve 6, and flows through the outdoor expansion valve 6, which is controlled so that the valve tends to open, so that it flows into the outdoor heat exchanger 7. The coolant flowing into the outdoor heat exchanger 7 is cooled by flowing therein or by the outside air passing through the outdoor fan 15 to condense. The coolant flowing out of the outdoor heat exchanger 7 flows out of the coolant pipe 13A through the solenoid valve 17, then flows into the receiving drying section 14 and the subcooling section 16. Here, the coolant is subcooled.

[0055] The refrigerant flowing out of the subcooling section 16 of the outdoor heat exchanger 7 flows through the check valve 18 to enter the refrigerant pipe 13B, and flows through the indoor heat exchanger 19 to reach the indoor expansion valve 8. The refrigerant is expanded in 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 to the heat absorber 9 due to the heat absorption operation during this period, thus cooling and dehumidifying the air.

[0056] The refrigerant evaporated in the heat absorber 9 flows through the evaporation capacity control valve 11, the interior heat exchanger 19, and the refrigerant pipe 13C to reach the accumulator 12, and flows therethrough to be sucked into the compressor 2, repeating this circulation. The air cooled and dehumidified in the heat absorber 9 is reheated (a heating capacity is smaller than that during heating) in the process of passing through the heater core 4, thus achieving dehumidification and cooling of the vehicle interior.The control device 32 controls the rotation speed of the compressor 2 based on the temperature of the heat absorber 9 detected by the heat absorber temperature sensor 48, and also controls the valve position of the outdoor expansion valve 6 based on the above-described high pressure of the refrigerant circuit R, and controls a refrigerant pressure (a radiator pressure Pci) of the radiator 4. (5) Flow of coolant in cooling mode

[0057] Next, in the cooling mode, the control device 32 opens the solenoid valve 20 in the above-described state of the dehumidification and cooling mode (in this case, the outdoor expansion valve 6 can have any valve position including a fully open position (the valve position is set to an upper limit of the control)), and the air mixing damper 28 has a state where the air does not pass through the radiator 4 and the heating medium / air heat exchanger 40. Consequently, the high-temperature and high-pressure refrigerant gas discharged from the compressor 2 flows into the radiator 4. The air in the air flow channel 3 does not pass through the radiator 4, so the air only passes through here, and the refrigerant flowing out of the radiator 4 flows through the refrigerant pipe 13E to reach the solenoid valve 20 and the outdoor expansion valve 6.

[0058] At this time, the solenoid valve 20 is opened, and thus the refrigerant bypasses the outdoor expansion valve 6 to pass through the bypass pipe 13J and flows into the outdoor heat exchanger 7 as it is. The refrigerant is cooled by passing through it or by the outside air passing through the outdoor fan 15 to condense and liquefy. The refrigerant flowing out of the outdoor heat exchanger 7 flows out of the refrigerant pipe 13A through the solenoid valve 17 to sequentially flow into the receiving drying section 14 and the subcooling section 16. At this time, the refrigerant is subcooled.

[0059] The refrigerant flowing out of the subcooling section 16 of the outdoor heat exchanger 7 flows through the check valve 18 to enter the refrigerant pipe 13B, and flows through the indoor heat exchanger 19 to reach the indoor expansion valve 8. The refrigerant is expanded 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 during this period, so that the air is cooled.

[0060] The refrigerant evaporated in the heat absorber 9 flows through the evaporation capacity control valve 11, the indoor heat exchanger 19, and the refrigerant pipe 13C to reach the accumulator 12, and flows therethrough to be sucked into the compressor 2, repeating this circulation. The air cooled and dehumidified in the heat absorber 9 does not pass through the radiator 4, but is blown out of the outlet 29 into the vehicle interior, thus cooling the vehicle interior. In this cooling mode, the controller 32 controls the rotational speed of the compressor 2 based on the temperature of the heat absorber 9 detected by the heat absorber temperature sensor 48. (6) Heating mode and auxiliary heating by the heating medium circulation circuit (auxiliary heating device) in the heating mode

[0061] Next, the control of the compressor 2 and the outdoor expansion valve 6 in the heating mode and the auxiliary heating by the heating medium circulation circuit 23 in the heating mode will be described. (6-1) Control of the compressor and the outdoor expansion valve

[0062] The control device 32 calculates a target outlet temperature TAO from the equation (I) shown below. The target outlet temperature TAO is a target temperature of the air blown out of the outlet 29 into the vehicle interior. TAO = (Tset − Tin)× K + Tbal(f(Tset, SUN, Tam)) where Tset is a predetermined temperature in the vehicle interior set by the air conditioning operating section 53, Tin is a temperature of the air in the vehicle interior detected by the inside air temperature sensor 37, K is a coefficient, and Tbal is a balance value calculated from the predetermined temperature Tset, an amount of solar irradiation SUN detected by the inside air temperature sensor 51, and an outside air temperature Tam detected by the outside air temperature sensor 33. Furthermore, in general, the lower the outside air temperature Tam, the higher the target exit temperature TAO, and the higher the outside air temperature Tam, the lower the target exit temperature TAO.

[0063] The control device 32 calculates a radiator target temperature TCO from the target outlet temperature TAO, and next, it calculates a radiator target pressure PCO based on the radiator target temperature TCO. Further, the control device 32 calculates a rotational speed Nc of the compressor 2 based on the radiator target pressure PCO and a refrigerant pressure (a radiator pressure) Pci of the radiator 4 detected by the radiator pressure sensor 47, and operates the compressor 2 at the rotational speed Nc. Namely, the control device 32 controls the refrigerant pressure Pci of the radiator 4 according to the rotational speed Nc of the compressor 2.

[0064] In addition, the control device 32 calculates a target radiator subcooling degree TGSC of the radiator 4 based on the target outlet temperature TAO. On the other hand, the control device 32 calculates a subcooling degree (a radiator subcooling degree SC) of the coolant in the radiator 4 based on the radiator pressure Pci and the temperature (a radiator temperature Tci) of the radiator 4 detected by the radiator temperature sensor 46. Further, the control device calculates a target valve position of the outdoor expansion valve 6 (a target outdoor expansion valve position TGECCV) based on the radiator subcooling degree SC and the target radiator subcooling degree TGSC. Further, the control device 32 controls the valve position of the outdoor expansion valve 6 according to the target outdoor expansion valve position TGECCV.

[0065] The control device 32 performs the calculation in such a direction that the target radiator subcooling degree TGSC increases as the target outlet temperature TAO becomes higher, but the present invention is not limited to this example, and the control device may perform the calculation based on a difference (a capacity difference) between a required heating capacity Qtgt and a heating capacity Qhp (QhpNI) described below, or the radiator pressure Pci, or a difference (a pressure difference) between the target radiator pressure PCO and the radiator pressure Pci. In this case, the control device 32 decreases the target radiator subcooling degree TGSC as the capacity difference becomes smaller, the pressure difference becomes smaller, an air volume of the indoor fan 27 becomes smaller, or the radiator pressure Pci becomes smaller. (6-2) Control of the heating medium circulation circuit

[0066] When the control device 32 determines that the heating capacity by the radiator 4 is becoming scarce in this heating mode, the control device additionally energizes the electric heating medium heater 35 to generate heat and operates the circulation pump 30, thereby performing heating by the heating medium circulation circuit 23.

[0067] When the circulation pump 30 of the heating medium circulation circuit 23 is actuated and the electric heating medium heater 35 is energized, the heating medium (the high-temperature heating medium) heated by the electric heating medium heater 35 as described above is circulated through the heating medium / air heat exchanger 40, and thus the air passing through the heater core 4 of the air flow channel 3 is heated. Fig. 3 shows the temperatures of the respective components in the air flow channel 3 during this period. In this drawing, Ga is an air mass volume of the air flowing into the air flow channel 3, Te is the temperature of the heat absorber 9 detected by the heat absorber temperature sensor 48 (the temperature of the air flowing out of the heat absorber 9), GaxSW is a value obtained by multiplying the air mass volume Ga by an opening of the air mixing damper 28, THhp is a temperature of the air that has passed through the radiator 4 detected by the radiator temperature sensor 46 (ie,The heater core temperature Tci), and TH is a temperature of the air that has passed through the heating medium / air heat exchanger 40, which is detected by the heating medium / air heat exchanger temperature sensor 55, and in the heating mode, a set value of the temperature of the air flowing out of the heating medium / air heat exchanger 40 and blown out of the outlet 29 to the vehicle interior is the heater core target temperature TCO. Note that TH = THp when the heating medium circulation circuit 23 is not operating.

[0068] Next, the control of the heating medium circulation circuit 23 in the heating mode described above will be explained with reference to the Fig. 4 to 6. In this invention, the control device 32 calculates the required heating capacity Qtgt, which is the heating capacity required for the radiator 4, using the equation (II) described below, and predicts and calculates a required refrigerant evaporation temperature TXObaseQtgt at non-icing, which is a refrigerant evaporation temperature of the outdoor heat exchanger 7, in order to realize the required heating capacity Qtgt at non-icing of the outdoor heat exchanger 7, that is, when the outdoor heat exchanger 7 is not icy, by using the equation (III) mentioned below.Further, the control device predicts and calculates a target value of a maximum heating capacity to be generated by the heater core 4 in a region where the outdoor heat exchanger 7 is not frosted by the equation (IV) mentioned below, that is, it predicts and calculates a predicted value of the maximum heating capacity without frosting QmaxNfst, which is the target value of the maximum heating capacity to be generated by the heater core 4 without causing frost formation on the outdoor heat exchanger 7 when a heat pump operation is performed to cause the coolant to radiate heat in the heater core 4 and to evaporate the coolant in the outdoor heat exchanger 7 in an environment where the vehicle is currently placed. Qtgt=(TCO−Te)×Cpa×ρ×Qair TXObaseQtgt '' f(Tam, Qtgt) QmaxNfst = f(Tfrost, Tam) where Tam is the above-described outside air temperature detected by the outside air temperature sensor 33, Te is the temperature of the heat absorber 9 detected by the heat absorber temperature sensor 48, Cpa is a specific heat [kj / kg·K] of the air flowing into the heater core 4, ρ is a density (a specific volume) [kg / m 3 ] of the air flowing into the radiator 4 and Qair is a volume [m 3 / h] of the air passing through the radiator 4 (estimated from an electric fan voltage BLV of the indoor fan 27 or the like). In addition, Tfrost is a frost point, and it will be described later.

[0069] Note that in equation (II), the temperature of the air flowing into the heater 4 or the temperature of the air flowing out of the heater 4 may be used instead of or in addition to Qair. In addition, the predicted value of the maximum heating capacity QmaxNfst without frosting may be corrected by referring to the respective environmental conditions or external information, such as a time, the amount of solar irradiation detected by the solar irradiation sensor 51, rainfall, a location, and weather in addition to the outside air temperature Tam in equation (IV).

[0070] In this invention, the controller 32 additionally calculates the frost point Tfrost, which is a temperature of the outside air around the outdoor heat exchanger 7 at which the outdoor heat exchanger 7 is frosted (a temperature at which a water vapor pressure in the outside air is equal to a saturated water vapor pressure of ice), based on the outside air temperature detected by the outside air temperature sensor 33 and the outside humidity of the vehicle detected by the outside air humidity sensor 34. A calculation method of the frost point Tfrost is conventional, and thus, its description is omitted.

[0071] The control device 32 reads data from the respective sensor at a step S1 in a flowchart of the Fig. 4, and determines whether the above-described heating mode is selected or not at a step S2. If the heating mode is selected, the control device 32 further proceeds to a step S3 to calculate the required heating capacity Qtgt using the equation (II) mentioned above. (6-3) Control immediately after starting the heating mode

[0072] Next, at step S4, the control device 32 determines whether or not it is immediately after the start (ON) of the heating mode. In winter, it is determined that the vehicle has been started immediately, but this determination of whether or not it is immediately after the start is made by determining whether or not a predetermined time or less has elapsed after such a start of the vehicle, or whether or not a predetermined time or less has elapsed after other mode switching to the heating mode.It should be noted that the determination of whether or not it is immediately after the start does not depend on such a temporary determination, and can be made, for example, by determining whether or not a difference Tset - Tin between a predetermined temperature Tset in the vehicle interior and a temperature Tin of air in the vehicle interior is larger than a predetermined value (Tset - Tin > the predetermined value).

[0073] Furthermore, when it is immediately after the start, the controller 32 proceeds from step S4 to step S5, and calculates the non-icing required refrigerant evaporation temperature TXObaseQtgt (an estimated value) using the above-described equation (III) from the outside air temperature Tam and the required heating capacity Qtgt. Next, the controller 32 compares the calculated non-icing required refrigerant evaporation temperature TXObaseQtgt with the frost point Tfrost, and proceeds to step S7 when the non-icing required refrigerant evaporation temperature TXObaseQtgt is lower than the frost point Tfrost (TXObaseQtgt < Tfrost).

[0074] In step S7, the control device 32 calculates the predicted value of the maximum heating capacity QmaxNfst without frosting (an estimated value) from the frost point Tfrost and the outside air temperature Tam using the above-described equation (IV). Fig. Figure 5 shows a relationship between the predicted value of the maximum heating capacity QmaxNfst without icing and the outside air temperature (a tendency of a change in the predicted value of the maximum heating capacity without icing). The maximum heating capacity Qhp that can be generated by the radiator 4 increases in proportion to an increase in the outside air temperature Tam. Furthermore, if the outside air temperature at which the outdoor heat exchanger 7 is not icy is defined as approximately +5°C and the operation is carried out with the maximum heating capacity Qhp as it is at +5°C or less, the outdoor heat exchanger 7 is icy. As shown by dashed lines in the Fig. 5, there is therefore a tendency that the predicted value of the maximum heating capacity QmaxNfst without icing decreases at an angle larger than the maximum heating capacity Qhp according to the decrease in the outside air temperature.

[0075] At a step S7, the predicted value of the maximum heating capacity QmaxNfst without icing is calculated (estimated), and then the control device 32 next calculates a target heating capacity TGQech of the heating medium circulation circuit 23. The target heating capacity TGQech of the heating medium circulation circuit 23 is calculated according to an equation (V) described below. TGQech=Qtgt−QmaxNfst

[0076] A shortcoming of the predicted value of the maximum heating capacity QmaxNfst without icing to the required heating capacity Qtgt is namely the target heating capacity TGQech of the heating medium circulation circuit 23.

[0077] Further, at a step S7, the control device 32 defines the target heating capacity TGQhp of the heater core 4 as the predicted value of the maximum heating capacity QmaxNfst without icing (TGQhp = QmaxNfst), and operates the compressor 2 of the refrigerant circuit R and the like so that the heater core 4 generates the predicted value of the maximum heating capacity QmaxNfst without icing.

[0078] In step S7, the control device 32 further controls the energization of the electric heating medium heater 35 and the operation of the circulation pump 30 such that the target heating capacity TGQech of the heating medium circulation circuit 23 = the required heating capacity Qtgt - the predicted value of the maximum heating capacity without icing QmaxNfst (the predicted value of the maximum heating capacity without icing QmaxNfst = the target heating capacity TGQhp of the radiator 4), based on outputs from the temperature sensor 50 of the electric heating medium heater and the temperature sensor 55 of the heating medium-to-air heat exchanger. Namely, the control device 32 compensates for the shortfall of the predicted value of the maximum heating capacity without icing QmaxNfst to the required heating capacity Qtgt by heating by the heating medium-to-air heat exchanger 40 of the heating medium circulation circuit 23.Consequently, comfortable heating of the vehicle interior can be realized and ice formation on the exterior heat exchanger 7 can be prevented.

[0079] A left side of a central vertical line in Fig. Figure 6 shows a situation at start-up, and it shows that heating (ECH output) is performed by the heating medium circulation circuit 23 when the required refrigerant evaporation temperature TXObaseQtgt under non-icing is lower than the frost point Tfrost. In this case, the predicted value of the maximum heating capacity QmaxNfst without icing is influenced by the outside air temperature Tam, the required refrigerant evaporation temperature TXObaseQtgt under non-icing is also influenced by the outside air temperature Tam, and there is a tendency for each value to decrease as the outside air temperature Tam decreases. Therefore, in a situation where the required refrigerant evaporation temperature TXObaseQtgt under non-icing becomes lower, the predicted value of the maximum heating capacity QmaxNfst without icing also decreases, and thus the target heating capacity TGQech (the ECH output in Fig. 6) of the heating medium circulation circuit 23.

[0080] On the other hand, for example, when the outside air temperature is comparatively high, and it is determined at step S6 that the required refrigerant evaporation temperature TXObaseQtgt in non-frosting is not lower than the frost point Tfrost (Tfrost ≤ TXObaseQtgt), the controller 32 proceeds to step S8, where the controller stops heating by the heating medium circulation circuit 23 (it stops the circulation pump 30 and stops ECH due to non-energization of the electric heating medium heater 35: TGQech = 0) and operates the compressor 2 of the refrigerant circuit R and the like, so that the radiator 4 generates the required heating capacity Qtgt (TGQhp = Qtgt). Consequently, unnecessary heating by the heating medium circulation circuit 23 can be avoided to prevent an increase in power consumption. (6-4) Control when not immediately after starting the heating mode

[0081] By coordinating heating of the heater core 4 and the heating medium circulation circuit 23 immediately after starting, as described above, frost formation on the outdoor heat exchanger 7 is prevented. However, due to subsequent vehicle travel, water in the outside air adheres as frost to the outdoor heat exchanger 7 in the heating mode. As this frost increases, heat exchange between the outdoor heat exchanger 7 and the passing outside air is significantly hindered, and air conditioning performance deteriorates. (6-5) Estimating ice formation on the outdoor heat exchanger

[0082] Thus, when not at step S4 immediately after the start of the heating mode, for example, when the vehicle is traveling for a predetermined time or longer after the start, the control device 32 proceeds to step S9 to estimate the state of frost formation on the outdoor heat exchanger 7 by the frost formation state estimation means as a function inherent to the control device 32. Next, an estimation example of the frost formation determination on the outdoor heat exchanger 7 in this embodiment will be described with reference to a right side from the central vertical line of the Fig. 6 described.

[0083] The controller 32 estimates the state of frost formation on the outdoor heat exchanger 7 based on the frost point Tfrost and a current refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 obtained from the outdoor heat exchanger pressure sensor 56. Namely, the controller 32 calculates a difference (Tfrost-TXO) between the frost point Tfrost and the current refrigerant evaporation temperature TXO, and determines that frost formation on the outdoor heat exchanger 7 is progressing when the refrigerant evaporation temperature TXO drops below the frost point Tfrost and a state in which the difference is greater than a predetermined frost detection threshold ΔT1 persists, for example, at a predetermined frost detection state estimation time.

[0084] A dashed line in Fig. Figure 6 shows a change in the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7. At the beginning of operation (at startup) (the left side of the center vertical line), the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 is greater than the frost point Tfrost. As frost formation begins on the outdoor heat exchanger 7 as the heating mode progresses, the heat exchange function with the outside air gradually deteriorates, and thus the refrigerant evaporation temperature TXO (the dashed line) decreases, and finally falls below the frost point Tfrost on the right side of the center vertical line.

[0085] Furthermore, when the coolant evaporation temperature TXO continues to drop and the difference (Tfrost-TXO) is greater than the frost detection threshold ΔT1, and this condition continues for the predetermined estimation time or longer, the controller 32 determines the frost progression. The frost progression includes both a case where frost is actually formed on the outdoor heat exchanger 7 and a case where there is a high probability of frost formation occurring on the outdoor heat exchanger 7, that is, a case where frost formation is predicted with a high probability. (6-6) Prevention of ice formation on the outdoor heat exchanger

[0086] When the control device 32 determines the progress of frost formation of the outdoor heat exchanger 7 at step S9, the control device proceeds to step S10 to calculate the target heating capacity TGQech of the heating medium circulation circuit 23 using an equation (VI) described below. TGQech=f(Tfrost−TXO) where TGQech ≥ 0. The difference (Tfrost - TXO) between the frost point Tfrost and the coolant evaporation temperature TXO of the outdoor heat exchanger 7 represents a degree of frost formation on the outdoor heat exchanger 7 for a reason such as that described above. Namely, the control device 32 calculates the target heating capacity TGQech of the heating medium circulation circuit 23 based on the degree of frost formation on the outdoor heat exchanger 7.

[0087] In step S10, the control device 32 further defines the target heating capacity TGQhp of the radiator 4 as a value (Qtgt - TGQech) obtained by subtracting the target heating capacity TGQech of the heating medium circulation circuit 23 from the required heating capacity Qtgt. Thus, the target heating capacity TGQhp of the radiator 4 is reduced, and thus the target heating capacity TGQech of the heating medium circulation circuit 23 becomes a heating capacity for inhibiting or preventing frost formation on the outdoor heat exchanger 7.

[0088] The right side of the vertical middle line of the Fig. 6 is a graph showing a change in the target heating capacity TGQech of the heating medium circulation circuit 23. In this case, the controller 32 detects the frost formation state or degree of frost formation according to the frost point value Tfrost - the refrigerant evaporation temperature TXO. Furthermore, when the state where TXO is lower than Tfrost continues for the predetermined time as described above, the controller 32 increases TGQech according to the increase in the difference (Tfrost - TXO).

[0089] Note that, at step S11, the controller 32 determines whether the target heating capacity TGQhp of the radiator 4 calculated at step S10 is greater than a significantly smaller predetermined value Q1 or not. If TGQhp>Q1, the controller 32 further proceeds to step S12 and controls the energization of the electric heating medium heater 35 and the operation of the circulation pump 30 to achieve the target heating capacity TGQech (= f(Tfrost - TXO)) calculated according to the above-described equation (VI) based on the outputs from the electric heating medium heater temperature sensor 50 and the heating medium-air heat exchanger temperature sensor 55.

[0090] Namely, the control device 32 controls the heating by the heating medium circulation circuit 23 based on the degree of frost formation on the outdoor heat exchanger 7, and the target heating capacity TGQhp of the radiator 4 is obtained as a value (Qtgt - TGQech) by subtracting the target heating capacity TGQech of the heating medium circulation circuit 23 from the required heating capacity Qtgt.

[0091] On the other hand, when the target heating capacity TGQhp of the radiator 4 calculated at step S10 is excessively small and the above-described value Q1 or less, the control device 32 proceeds from step S11 to step S13, stops the compressor 2 of the refrigerant circuit R to stop heating by the radiator 4 (stopping HP: TGQhp = 0), and controls the energization of the electric heating medium heater 35 and the operation of the circulation pump 30 so that the heating medium-air heat exchanger 40 of the heating medium circulation circuit 23 generates the required heating capacity Qtgt (TGQech = Qtgt).

[0092] Here, when the target heating capacity TGQhp of the heater core 4 is excessively small, the heating capacity can be ignored, and the suction air temperature of the heater core 4 substantially coincides with a temperature of the air passing through the heater core 4, so that the coolant circuit R becomes inefficient. When the target heating capacity TGQhp of the heater core 4 is excessively small (Q1 or less) as in the embodiment, at step S14, the target heating capacity TGQhp = 0 for the heater core 4 is achieved, and thus the deterioration of the efficiency can be avoided in advance.

[0093] It should be noted that, when the difference (Tfrost - TXO) is equal to or smaller than ΔT1 at step S9, the controller 32 determines that the frost formation on the outdoor heat exchanger 7 is not progressing, that is, the frost formation has not yet grown, and the controller proceeds to step S8, stops heating by the heating medium circulation circuit 23 (stops the circulation pump 30 and does not energize the heating medium electric heater 35 to stop ECH (TGQech = 0)), and operates the compressor 2 of the refrigerant circuit R and the like so that the radiator 4 generates the required heating capacity Qtgt (TGQhp = Qtgt).

[0094] As described in detail above, in the present invention, the heating medium / air heat exchanger 40 of the heating medium circulation circuit 23 is arranged to heat the air to be supplied from the air flow duct 3 into the vehicle interior, and the control device 32 calculates the required refrigerant evaporation temperature TXObaseQtgt at non-icing, which is the refrigerant evaporation temperature of the outdoor heat exchanger 7 when the required heating capacity Qtgt, which is the heating capacity required for the heater core 4, is realized at non-icing of the outdoor heat exchanger 7, and the control device controls the heating by the heater core 4 and the heating by the heating medium / air heat exchanger 40 of the heating medium circulation circuit 23 based on the required refrigerant evaporation temperature TXObaseQtgt at non-icing and the frost point Tfrost to obtain the required heating capacity Qtgt. to reach,without causing ice formation on the outdoor heat exchanger 7. Therefore, the required heating capacity Qtgt is achieved by the coordinated heating of the radiator 4 and the heating medium circulation circuit 23 without causing ice formation on the outdoor heat exchanger 7, based on the frost point Tfrost at which the outdoor heat exchanger 7 is iced, and it is possible to realize comfortable heating of the vehicle interior.

[0095] In this case, the control device 32 calculates the required non-icing refrigerant evaporation temperature TXObaseQtgt based on the outside air temperature Tam and the required heating capacity Qtgt, and thus it is possible to accurately estimate the required non-icing refrigerant evaporation temperature TXObaseQtgt that realizes the required non-icing heating capacity Qtgt of the outdoor heat exchanger 7 and effectively prevent frost formation on the outdoor heat exchanger.

[0096] In addition, the control device 32 calculates the predicted value of the maximum heating capacity without icing QmaxNfst, which is a target value of the maximum heating capacity to be generated by the radiator 4 in a region where the outdoor heat exchanger 7 is not icy, and the control device defines the target heating capacity TGQhp of the radiator 4 as the predicted value of the maximum heating capacity without icing QmaxNfst, and compensates for the deficiency of the predicted value of the maximum heating capacity without icing QmaxNfst to the required heating capacity Qtgt by heating by the heating medium / air heat exchanger 40 of the heating medium circulation circuit 23 when the required refrigerant evaporation temperature TXObaseQtgt in non-icing is lower than the frost point Tfrost.Furthermore, when the required coolant evaporation temperature TXObaseQtgt in non-icing is the frost point Tfrost or higher, the control device defines the target heating capacity TGQhp of the heater core 4 as the required heating capacity Qtgt, and stops heating by the heating medium circulation circuit 23, and thus it is possible to minimize the deterioration of the efficiency due to heating by the heating medium circulation circuit 23. Consequently, it is possible to effectively suppress the disadvantage that the cruising range decreases, particularly in the electric vehicle.

[0097] In addition, the control device 32 calculates the predicted value of the maximum heating capacity QmaxNfst without icing based on the frost point Tfrost and the outside air temperature Tam, and thus it is possible to accurately estimate the predicted value of the maximum heating capacity QmaxNfst without icing at which the outdoor heat exchanger 7 is not icy and effectively prevent icing on the outdoor heat exchanger 7.

[0098] Furthermore, the control device 32 executes the above-described control based on the required non-icing coolant evaporation temperature TXObaseQtgt and the frost point Tfrost immediately after startup, so that it is possible to prevent the disadvantage that frost formation on the outdoor heat exchanger 7 begins due to startup after a state in which the vehicle is stopped, that is, a state in which the outdoor heat exchanger 7 is not yet frosted, and it is possible to suppress the growth of frost formation due to subsequent travel as much as possible. In addition, the control device estimates the required non-icing coolant evaporation temperature TXObaseQtgt only immediately after startup to perform compensation by the heating medium circulation circuit 23, and thus it is also possible to achieve a reduction in power consumption.

[0099] In addition, the control device 32 estimates the state of frost formation on the outdoor heat exchanger 7, and performs heating through the heating medium circulation circuit 23 when frost formation occurs on the outdoor heat exchanger 7 or when frost formation on the outdoor heat exchanger 7 is predicted in a case where it is not immediately after start-up, and thus it is possible to provide the heating capacity of the vehicle interior while effectively preventing or suppressing frost formation on the outdoor heat exchanger 7 during travel after start-up.

[0100] Furthermore, the control device 32 calculates the target heating capacity TGQech of the heating medium circulation circuit 23 based on the degree of frost formation on the outdoor heat exchanger 7, thereby inhibiting or preventing frost formation on the outdoor heat exchanger 7, and the control device obtains the value of the target heating capacity TGQhp of the heater core 4 by subtracting the target heating capacity TGQech of the heating medium circulation circuit 23 from the required heating capacity Qtgt. Therefore, heating by the heating medium circulation circuit 23 is accurately controlled while inhibiting or preventing frost formation on the outdoor heat exchanger 7, and thus comfortable heating of the vehicle interior can be realized.

[0101] In this case, too, it is additionally possible to minimize the deterioration of the efficiency due to heating by the heating medium circulation circuit 23, and thus it is also possible to effectively prevent a reduction in the driving range of the electric vehicle.

[0102] In this case, when the target heating capacity TGQhp of the radiator 4 is smaller than the predetermined value, the control device 32 stops the operation of the compressor 2, and thus the deterioration of the efficiency in a situation where the heating of the radiator 4 is excessively low can be avoided in advance.

[0103] Specifically, the control device 32 estimates the frost formation state on the outdoor heat exchanger 7 or the degree of frost formation on the outdoor heat exchanger 7 based on the frost point Tfrost and the coolant evaporation temperature TXO of the outdoor heat exchanger 7. Thus, the frost formation on the outdoor heat exchanger 7 can be accurately determined, and the above-described control can be performed. Consequently, heating by the heating medium circulation circuit 23 can be accurately controlled, and it is possible to suppress an increase in power consumption.

[0104] Furthermore, in the embodiment, the auxiliary heating means is constituted by the heating medium circulation circuit having the heating medium / air heat exchanger 40 for heating the air to be supplied from the air flow duct 3 into the vehicle interior, the electric heating medium heater 35, and the circulation pump 30, and circulates the heating medium heated by the electric heating medium heater 35 through the heating medium / air heat exchanger 40 through the circulation pump 30, and thus electrically safe heating in the vehicle interior can be realized. Example 2

[0105] Next, Fig. 7 shows another embodiment of a flowchart of a control device 32. It should be noted in this drawing that steps designated by the same reference numerals show the same or similar commands. In this embodiment, in a comparison of a required evaporation temperature TXObaseQtgt in the absence of icing with a frost point Tfrost in a step S6, a predetermined value α1 is added to this frost point Tfrost. Furthermore, in an equation (IV) for calculating the predicted value of the maximum heating capacity QmaxNfst without icing, which is executed in a step S7, +α1 is added to the frost point Tfrost: QmaxNfst=f(Tfrost+∝1,Tam)

[0106] If +α1 is added to the frost point Tfrost, a line of the frost point Tfrost also rises in this example. Fig. 6, and thus the heating (ECH output) is enhanced by a heating medium circulation circuit 23. Consequently, a margin is set in the prevention of frost formation or the like on the outdoor heat exchanger 7, and it is possible to realize the prevention or suppression of frost formation more securely. Example 3

[0107] Next, the Fig. 8 shows another embodiment of a flowchart of a control device 32. It should be noted in this drawing that the same sections as those indicated by F1 and F2 in the flowcharts of Fig. 4 and Fig. 7 are designated by the same reference numerals, and details are omitted. In this embodiment, at step S9, a difference (Tfrost - TXO) is equal to or smaller than ΔT1, and frost formation on an outdoor heat exchanger 7 is not progressing. Namely, when it is determined that frost formation is not occurring on the outdoor heat exchanger 7, the control device directly proceeds to step S8 and does not place an electric heating medium heater 35 in a non-energized state, but performs stage control at step S14 in this case.

[0108] The Fig. Figure 8 shows the step control of step S14 of this embodiment in its lower part. When it is no longer immediately after the start of a heating mode, that is, when the control device proceeds from step S4 to step S9 and the difference (Tfrost - TXO) is equal to or smaller than ΔT1, the control device 32 gradually or in stages decreases a target heating capacity TGQech of a heating medium circulation circuit 23 in step S14.

[0109] On the other hand, a target heating capacity TGQhp of a radiator 4 is calculated according to TGQhp = Qtgt - TGQech similarly to step S10. Therefore, the target heating capacity TGQhp of the radiator 4 is increased gradually or in stages. Further, the controller finally proceeds to step S8, where heating by the heating medium circulation circuit 23 is stopped (a circulation pump 30 is stopped and the electric heating medium heater 35 is de-energized to stop ECH: TGQech = 0), and the controller operates a compressor 2 of a refrigerant circuit R and the like so that the radiator 4 generates a required heating capacity Qtgt (TGQhp = Qtgt).

[0110] Here, a change in the heating capacity to be generated by the radiator 4 under operation control of the compressor 2 may be delayed after a decrease in the heating capacity by the heating medium-air heat exchanger 40 due to a stop of the supply of the high-temperature heating medium to the heating medium-air heat exchanger 40 of the heating medium circulation circuit 23. In addition, if the control device proceeds to step S8 after step S9, in which the target heating capacity TGQech of the heating medium circulation circuit 23 is 0 and the target heating capacity TGQhp of the radiator 4 rapidly increases to the required heating capacity Qtgt, there is a risk that frost will be temporarily formed on the outdoor heat exchanger 7 depending on the ambient conditions.

[0111] However, when the control device 32 determines that frost is not formed on the outdoor heat exchanger 7, as in this embodiment, at step S14, the control device gradually or in stages lowers the heating by the heating medium-air heat exchanger 40 of the heating medium circulation circuit 23 and finally stops the heating. In this case, it is possible to suppress a disadvantage that a temperature of the air to be blown to a vehicle interior is rapidly changed due to such a delay in the increase of the heating capacity of the heater core 4. In addition, the target heating capacity TGQhp of the heater core 4 is gradually or in stages increased, and thus, transient frost formation on the outdoor heat exchanger 7 can be prevented or suppressed. Example 4

[0112] Next, the Fig. 9 is a structural view of another embodiment of the vehicle air conditioning device 1 of the present invention. In this embodiment, no receiving drying section 14 and no sub-cooling section 16 are disposed in an outdoor heat exchanger 7, and a coolant pipe 13A extending from the outdoor heat exchanger 7 is connected to a coolant pipe 13B via a solenoid valve 17 and a check valve 18. In addition, a coolant pipe 13D branching from the coolant pipe 13A is similarly connected to a coolant pipe 13C on a downstream side of an indoor heat exchanger 19 via a solenoid valve 21.

[0113] The rest of the structure is similar to the example of Fig. 1. The present invention is also effective in the vehicle air conditioning device 1 having a refrigerant cycle R in which the outdoor heat exchanger 7, which does not require the receiving drying section 14 and the sub-cooling section 16, is used in this manner. Example 5

[0114] Next, the Fig. 10 is a structural view of another embodiment of the vehicle air conditioning device 1 of the present invention. Note that a refrigerant circuit R of this embodiment is similar to that shown in FIG. Fig. 9. In this case, a heating medium / air heat exchanger 40 of a heating medium circulation circuit 23 is additionally arranged on an upstream side of a radiator 4 to the air flow of an air flow duct 3, which is a downstream side of an air mixing damper 28. The remaining structure is similar to that in the Fig. 9.

[0115] In this case, the heating medium / air heat exchanger 40 is positioned on the upstream side of the heater core 4 in the air flow channel 3, and thus, during operation of the heating medium circulation circuit 23, the air is heated by the heating medium / air heat exchanger 40 and then flows into the heater core 4. The present invention is also effective in the vehicle air conditioning device 1 in which the heating medium / air heat exchanger 40 is arranged on the upstream side of the heater core 4 in this manner, and particularly in this case, no problem due to a low temperature of a heating medium in the heating medium circulation circuit 23 occurs.Consequently, coordinated heating with the radiator 4 is simplified, and a so-called preliminary operation for heating the heating medium in advance is not required, but the air that has passed through the heating medium / air heat exchanger 40 disadvantageously flows into the radiator 4, and thus a temperature difference from the radiator 4 decreases, posing a risk of deteriorating heat exchange efficiency. On the other hand, if the heating medium / air heat exchanger 40 is arranged on the downstream side of the radiator 4 to the air flow of the air flow channel 3, as shown in FIGS. Fig. 1 and Fig. 9, the air heated by the heating medium / air heat exchanger 40 does not flow into the radiator 4, and the temperature difference between the temperature of the radiator 4 and that of the air can be acquired to prevent deterioration of a heat exchange function in the radiator 4, when compared with the case where the heating medium / air heat exchanger 40 is arranged on the upstream side of the radiator 4 as shown in FIG. Fig. 10 is shown. Example 6

[0116] Next, the Fig. 11 is a structural view of another embodiment of the vehicle air conditioning device 1 of the present invention. Main components of a coolant circuit R and a heating medium circulation circuit 23 of this embodiment are similar to those in Fig. 1, but a heating medium / coolant heat exchanger 70 is arranged in the heating medium circulation circuit 23. The heating medium / coolant heat exchanger 70 performs heat exchange between a heating medium pipe 23A extending from a circulation pump 30 and a coolant pipe 13E extending from a radiator 4 of the coolant circuit R. In the heating medium / coolant heat exchanger 70, a heating medium discharged from the circulation pump 30 is subjected to heating by a coolant flowing out of the radiator 4. Consequently, the heat from the coolant passing through the radiator 4 can be collected by the heating medium circulating through the heating medium circulation circuit 23.

[0117] Thus, in the heating medium circulation circuit 23, the heating medium / coolant heat exchanger 70 is arranged, which collects heat from the coolant passing through the radiator 4, and thus the heat that the coolant passing through the radiator 4 has is collected by the heating medium flowing in the heating medium circulation circuit 23 and is conveyed to a heating medium / air heat exchanger 40, so that it is possible to assist heating more effectively. Example 7

[0118] Next, the Fig. 12 is a structural view of another embodiment of the vehicle air conditioning device 1 of the present invention. A coolant circuit R and a heating medium circulation circuit 23 of this embodiment are similar to those in Fig. 11, but a heating medium / air heat exchanger 40 of the heating medium circulation circuit 23 is arranged on an upstream side of a radiator 4 and on a downstream side of an air mixing damper 28 to the air flow of an air flow duct 3. According to such a structure, heat having a coolant discharged from the radiator 4 is also collected by a heating medium flowing in the heating medium circulation circuit 23 in a heating medium / coolant heat exchanger 70 and is supplied to the heating medium / air heat exchanger 40, so that it is possible to further effectively support heating. Example 8

[0119] Next, the Fig. 13 is a structural view of another embodiment of the vehicle air conditioning device 1 of the present invention. Piping structures of a coolant circuit R and a heating medium circulation circuit 23 of this embodiment are substantially the same as those in Fig. 1, but a heater core 4 is not arranged in an air flow channel 3, but is arranged outside the air flow channel. Instead, in this case, a heating medium / coolant heat exchanger 74 with a heat exchange relationship is arranged in the heater core 4.

[0120] The heating medium / coolant heat exchanger 74 is connected to a heating medium pipe 23A between a circulation pump 30 of the heating medium circulation circuit 23 and an electric heating medium heater 35, and the heating medium / air heat exchanger 40 of the heating medium circulation circuit 23 is arranged in the air flow passage 3. According to such a structure, heat exchange is effected between a heating medium discharged from the circulation pump 30 and a coolant flowing through the radiator 4, and the heating medium is heated by the coolant. It is next heated by the electric heating medium heater 35 (in a case where the heater is energized to generate heat), and then radiates heat in a heating medium / air heat exchanger 40, thereby heating air to be supplied from the air flow passage 3 to a vehicle interior.

[0121] Also, in the vehicle air conditioning device 1 having such a structure, the electric heating medium heater 35 is energized to heat the heating medium flowing in the heating medium pipe 23A when a heating capacity by the heater core 4 becomes scarce, so that it is possible to assist heating and realize electrically safe heating of the vehicle interior when compared with a case where the electric heater is arranged in the air flow passage 3 as will be described later. Example 9

[0122] It should be noted that in the respective embodiments described above, a heating medium circulation circuit 23 is used as an auxiliary heating means, but the auxiliary heating means may be constituted by an ordinary electric heating device 73 (e.g., a PTC heater). Fig. 14 shows an example of a construction according to the Fig. 1 in this case, and the Fig. 15 shows a construction example according to the Fig. 9. In the Fig. 14 and Fig. 15 is in this case the heating medium circulation circuit 23 of the Fig. 1 and Fig. 9 is replaced by the electric heating device 73.

[0123] The remaining structure and control are substantially the same, and a control device 32 controls energization of the electric heater 73 instead of the circulation pump 30 and the electric heating medium heater 35 of the heating medium circulation circuit 23 to supplement a heating capacity of a radiator 4 with heat generated by the electric heater in the same manner as described above, so detailed descriptions are omitted. Thus, air to be supplied to a vehicle interior can be heated by the electric heater 73, and such a structure is advantageously simplified compared with the case where the heating medium circulation circuit 23 is used.

[0124] It goes without saying that the electric heating device 73 is mounted on an air upstream side of a radiator 4 of the Fig. 14 and Fig. 15 as in the case of Fig. 10, and in this case, there is an effect that it is possible to eliminate such a disadvantage that the temperature of the air to be supplied into the vehicle interior is lowered in an initial stage of starting the energization of the electric heater 73.

[0125] Note that, in the respective embodiments described above, the control device 32 as the frost formation state estimating means of the outdoor heat exchanger 7 estimates an frost formation state or a degree of frost formation on the outdoor heat exchanger 7 based on a frost point Tfrost and a refrigerant evaporation temperature TXO of the outdoor heat exchanger 7, but the inventions other than that of claim 11 are not limited to the embodiments, and the estimation may be performed by a procedure similar to that in the case of Tfrost and TXO based on a refrigerant evaporation temperature TXO (or a refrigerant evaporation pressure PXO) of the outdoor heat exchanger 7 and a refrigerant evaporation temperature TXObase (or a refrigerant evaporation pressure PXObase) of the outdoor heat exchanger 7 at non-frosting.In addition, for example, an actual heating capacity, which is the actual heating capacity of the radiator 4, is compared with a non-icing heating capacity, which is the heating capacity of the radiator 4 when the outdoor heat exchanger 7 is not iced, and it can be estimated that the outdoor heat exchanger 7 is iced when the actual heating capacity is smaller than the non-icing heating capacity.

[0126] Note that in the embodiments, the present invention is applied to the vehicle air conditioning device 1 that changes and executes various operation modes such as a heating mode, a dehumidifying and heating mode, a dehumidifying and cooling mode, and a cooling mode, but the present invention is not limited to these embodiments, and it is also effective for a vehicle air conditioning device that executes only the heating mode.

[0127] Moreover, in the embodiments, the heating medium circulation circuit 23 was described as the example of the auxiliary heating means, but the inventions other than that of claim 11 are not limited to the embodiments, and in the air flow passage 3, for example, an electric heater (the auxiliary heating means) may be arranged.

[0128] In addition, the structure of the refrigerant circuit R and the respective numerical values ​​described in the respective embodiments described above are not limitative, and needless to say, they can be changed without departing from the scope of the present invention. LIST OF REFERENCE SYMBOLS 1 vehicle air conditioning device 2 compressors 3 Air flow channel 4 radiators 6 Outdoor expansion valve 7 outdoor heat exchangers 8 Internal expansion valve 9 heat absorbers 11 Evaporation capacity control valve 17, 20, 21 and 22 solenoid valve 23 Heating medium circulation circuit (auxiliary heating device) 26 suction change damper 27 Internal fan (blower fan) 28 air mixing damper 30 Circulation pump (circulation device) 32 Control device (control equipment) 35 electric heating medium heating device (electric heating device) 40 heating medium / air heat exchangers R coolant circuit

Claims

[1] Vehicle air conditioning device (1) comprising: a compressor (2) which compresses a coolant; an air flow duct (3) through which air flows to be supplied to a vehicle interior, a heater (4) which causes the coolant to radiate heat to heat the air to be supplied from the air flow duct (3) into the vehicle interior; a heat absorber (9) which causes the coolant to absorb heat in order to cool the air to be supplied from the air flow duct (3) into the vehicle interior; an external heat exchanger (7) arranged outside the vehicle interior for causing the coolant to radiate or absorb heat; and a control device (32), wherein the control device (32) is configured to execute at least one heating mode in which the coolant discharged from the compressor (2) radiates heat in the radiator (4) and the coolant from which heat has been radiated is expanded and then absorbs heat in the outdoor heat exchanger (7), wherein the vehicle air conditioning device (1) comprises: an auxiliary heating device (23) for heating the air to be supplied from the air flow duct (3) into the vehicle interior, wherein the control device (32) is configured to calculate a required coolant evaporation temperature (TXObaseQtgt) in non-icing conditions, which is a coolant evaporation temperature of the outdoor heat exchanger (7) when a required heating capacity (Qtgt) as a heating capacity required for the radiator (4) is realized in non-icing conditions of the outdoor heat exchanger (7), and the control device (32) is further configured to control the heating by the radiator (4) and the heating by the auxiliary heating device (23) on the basis of the required coolant evaporation temperature (TXObaseQtgt) in non-icing conditions and a frost point (Tfrost) in order to achieve the required heating capacity (Qtgt) without causing frost formation on the outdoor heat exchanger (7), wherein the control device (32) is further configured toto calculate the required coolant evaporation temperature (TXObaseQtgt) in non-icing conditions based on an outside air temperature and the required heating capacity (Qtgt). [2] Vehicle air conditioning device (1) according to claim 1, wherein the control device (32) is further configured to calculate a predicted value of a maximum heating capacity (QmaxNfst) without icing, which is a target value of a maximum heating capacity (QmaxNfst) to be generated by the radiator (4) in an area in which the outdoor heat exchanger (7) is not icy, and the control device (32) is further configured to define a target heating capacity (TGQhp) of the radiator (4) as the predicted value of the maximum heating capacity (QmaxNfst) without icing and to compensate for a shortfall of the predicted value of the maximum heating capacity (QmaxNfst) without icing to the required heating capacity (Qtgt) by heating by the auxiliary heating device (23) when the required coolant evaporation temperature (TXObaseQtgt) in the absence of icing is lower than the frost point (Tfrost) or a temperature close to the frost point (Tfrost). [3] The vehicle air conditioning device (1) according to claim 2, wherein the control device (32) is configured to calculate the predicted value of the maximum heating capacity (QmaxNfst) without frosting based on the frost point (Tfrost) or the temperature near the frost point (Tfrost) and an outside air temperature. [4] The vehicle air conditioning device (1) according to any one of claims 1 to 3, wherein the control device (32) is further configured to define the target heating capacity (TGQhp) of the heater core (4) as the required heating capacity (Qtgt) and to stop heating by the auxiliary heater (23) when the required refrigerant evaporation temperature (TXObaseQtgt) in non-icing is the frost point (Tfrost) or a temperature close to the frost point (Tfrost) or greater. [5] The vehicle air conditioning device (1) according to any one of claims 1 to 4, wherein the control means (32) is configured to execute the control immediately after the start. [6] The vehicle air conditioning device (1) according to any one of claims 1 to 5, wherein the control device (32) comprises frost formation state estimation means for estimating a state of frost formation on the outdoor heat exchanger (7), and the control device (32) is further configured to execute heating by the auxiliary heating means (23) when frost formation occurs on the outdoor heat exchanger (7) or when frost formation on the outdoor heat exchanger (7) is predicted based on the estimation of the frost formation state estimation means in a case where it is not immediately after the start. [7] Vehicle air conditioning device (1) according to claim 6, wherein the control device (32) is configured to calculate a target heating capacity (TGQech) of the auxiliary heating device (23) for suppressing or preventing ice formation on the outdoor heat exchanger (7) on the basis of a degree of ice formation on the outdoor heat exchanger (7), and to obtain a value of the desired heating capacity (TGQhp) of the radiator (4) by subtracting the desired heating capacity (TGQech) of the auxiliary heating device (23) from the required heating capacity (Qtgt). [8] The vehicle air conditioning device (1) according to claim 7, wherein the control device (32) is configured to stop an operation of the compressor (2) when the target heating capacity (TGQhp) of the heater core (4) is less than a predetermined value. [9] The vehicle air conditioning device (1) according to any one of claims 6 to 8, wherein the control means (32) is configured to gradually or in stages lower the heating by the auxiliary heating means (23) and finally stop the heating when it is estimated that the outdoor heat exchanger (7) is not frosted based on the estimation by the frost formation state estimation means. [10] The vehicle air conditioning device (1) according to any one of claims 6 to 9, wherein the control device (32) is configured to estimate the state of frost formation or the degree of frost formation on the outdoor heat exchanger (7) based on the frost point (Tfrost) and a refrigerant evaporation temperature (TXO) of the outdoor heat exchanger (7). [11] The vehicle air conditioning device (1) according to any one of claims 1 to 10, wherein the auxiliary heating means (23) is constituted by a heating medium circulation circuit comprising a heating medium / air heat exchanger (40) for heating the air to be supplied from the air flow duct (3) into the vehicle interior, an electric heater (35) and a circulation means (30), and configured to circulate a heating medium heated by the electric heater (35) through the heating medium / air heat exchanger (40) through the circulation means (30).

Images