METHOD FOR OPERATING A VEHICLE AIR CONDITIONING DEVICE

Abstract

Method for operating a vehicle air conditioning system (1) with: a compressor (2) that compresses a refrigerant; an airflow channel (3) through which air flows to supply a vehicle interior; a radiator (4) which causes a refrigerant to radiate heat in order to heat the air which is to be supplied from the airflow duct (3) into the vehicle interior; a heat absorber (9) which causes the refrigerant to absorb heat in order to cool the air which is to be supplied from the airflow duct (3) into the vehicle interior; an external heat exchanger (7) located outside the vehicle interior to cause the refrigerant 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 refrigerant discharged from the compressor (2) radiates heat in the radiator (4) and the refrigerant from which the heat was radiated is expanded and then absorbs heat in the outdoor heat exchanger (7), wherein the vehicle air conditioning device (1) further 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) performs heating through the auxiliary heating device (23) when the heating capacity through the radiator (4) becomes insufficient, wherein the control device (32) compares a required heating capacity (Qtgt), which is the heating capacity required for the radiator (4), with a heating capacity (Qhp) to be generated by the radiator (4), and compensates for a deficiency of the heating capacity (Qhp) with respect to the required heating capacity (Qtgt) by heating the auxiliary heating device (23), wherein the heating capacity (Qhp) is a heating capacity in non-icing conditions (QhpNI) to be generated by the radiator (4) when the external heat exchanger (7) is not iced up, and any deficiency in the heating capacity in non-icing conditions (QhpNI) with respect to the required heating capacity (Qtgt) is compensated for by heating the auxiliary heating device (23), and wherein the control device (32) stops the compressor (2) and controls the auxiliary heating device (23) according to the required heating capacity (Qtgt) if an actual heating capacity (Qhpr) to be generated by the radiator (4) is less than the heating capacity when not icing (QhpNI) and a difference between the heating capacity when not icing (QhpNI) and the actual heating capacity (Qhpr) is greater than a predetermined value.

Description

TECHNICAL AREA

[0001] The present invention relates to a method for operating an air conditioning device of a heat pump system that conditions the air in a vehicle interior, and in particular relates to an air conditioning device that is applicable to a hybrid vehicle or an electric vehicle. STATE OF THE ART

[0002] Due to recent environmental problems, hybrid and electric vehicles have become widespread. Furthermore, an air conditioning system suitable for such vehicles has been developed, comprising a compressor for compressing and discharging a refrigerant, a radiator (condenser) located inside the vehicle to cause the refrigerant to radiate heat, a heat absorber (evaporator) located inside the vehicle to cause the refrigerant to absorb heat, and an external heat exchanger located outside the vehicle to cause the refrigerant to radiate or absorb heat. This system offers various modes, such as a heating mode in which the refrigerant discharged from the compressor radiates heat into the radiator.from which the heat was radiated in this radiator, absorbs heat in the external heat exchanger, a dehumidification mode in which the refrigerant released from the compressor radiates heat in the radiator and the refrigerant from which the heat was radiated in the radiator absorbs heat in the heat absorber, and a cooling mode in which the refrigerant released from the compressor radiates heat in the external heat exchanger and absorbs heat in the heat absorber (see e.g. JP 3 985 384 B2).

[0003] Additionally, the JP 3 985 384 B2 has an injection circuit that distributes the refrigerant released from the radiator, expands this distributed refrigerant, performs a heat exchange between this refrigerant and the refrigerant released from the radiator, and then returns the refrigerant to the intermediate compression by the compressor, thereby increasing the amount of refrigerant released from the compressor and improving the heating capacity of the radiator.

[0004] Furthermore, DE 10 2012 215 622 A1 relates to a refrigerant circuit device comprising a compressor, a user-side heat exchanger that heats a heat exchange fluid by carrying out heat exchange between the heat exchange fluid and the high-pressure refrigerant flowing from the compressor, an intermediate pressure passage through which gaseous intermediate pressure refrigerant, obtained by the decompression of the high-pressure refrigerant flowing from the user-side heat exchanger, is introduced into the intermediate pressure channel of the compressor, an external heat exchanger that evaporates low-pressure refrigerant, obtained by the decompression of high-pressure refrigerant flowing from the user-side heat exchanger, and causes the evaporated refrigerant to flow towards an intake channel of the compressor, and an auxiliary heater that heats the heat exchange fluid before or at the same time as the user-side heat exchanger heats the heat exchange fluid.

[0005] DE 10 2011 057 059 A1 relates to a heat pump system for a vehicle, comprising a water-cooled condenser which uses a coolant as a heat exchange medium and which uses waste heat generated by a motor and an electronic device to improve heating performance, efficiency and dehumidification performance.

[0006] DE 102 00 900 A1 relates to a vehicle air conditioning system in which a heat pump circuit is connected in parallel to the conventional cooling circuit with a compressor. The heat pump circuit absorbs heat from water flowing in the return line of an engine coolant circuit and then transfers this heat to the air flowing through the air duct via a second condenser provided in the air duct. The second condenser is located downstream of a heating element.

[0007] JP 2000 - 33 816 A concerns an air conditioning system for a vehicle. After a combustion heater is switched on and off for the first time during vehicle operation, the ambient temperature setpoint, which is the ON / OFF setpoint for the combustion heater, changes to a different ambient temperature setpoint. At this new setpoint, the combustion heater does not switch on as easily as with the first setpoint, in order to prevent repeated ON / OFF cycling. Furthermore, a condenser in the cabin, which serves as a primary heat source for heating the refrigerant and air, and the combustion heater, which serves as a secondary heat source for heating hot water and air, are installed in separate circuits. SUMMARY OF THE INVENTION Problems to be solved by the invention

[0008] However, if an outdoor heat exchanger ices up in an air conditioning system like the one described above, heat cannot be absorbed from the outside air, and thus the required heating capacity cannot be achieved. Additionally, the temperature of the refrigerant discharged from a radiator is low, further reducing the heat exchange between the refrigerant and the dispersed, expanded refrigerant. Therefore, when injecting a gas at the intermediate compression stage of a compressor, there is a limit to the amount of refrigerant that can flow through an injection circuit, and the amount of refrigerant discharged from the compressor cannot be increased sufficiently. As a result, the heating capacity cannot be adequately maintained.

[0009] The present invention was developed to solve such conventional technical problems, and its purpose is to heat a vehicle interior efficiently and comfortably with an air conditioning device of a so-called heat pump system. Means of solving the problems

[0010] According to a method for operating a vehicle air conditioning device of the present invention, the air conditioning device has a compressor that compresses a refrigerant, an airflow duct through which air flows to be supplied to a vehicle interior, a heater that causes the refrigerant to radiate heat to heat the air supplied from the airflow duct to the vehicle interior, a heat absorber that causes the refrigerant to absorb heat to cool the air supplied from the airflow duct to the vehicle interior, an external heat exchanger arranged outside the vehicle interior to cause the refrigerant to radiate or absorb heat, and a control device, wherein this control device is configured to execute at least one heating mode in which the refrigerant discharged from the compressor radiates heat in the heater and the refrigerant,from which the heat was radiated, is relaxed and then absorbs heat into the external heat exchanger, wherein the vehicle air conditioning device has an auxiliary heating device for heating the air which is to be supplied from the airflow duct to the vehicle interior, and which is characterized in that the control device performs the heating by means of the auxiliary heating device when the heating capacity by the radiator becomes insufficient.

[0011] The method for operating the vehicle air conditioning device of the invention according to claim 1 is further characterized in that the control device compares a required heating capacity Qtgt, which is the heating capacity required by the radiator, with a heating capacity Qhp to be generated by the radiator, and compensates for a deficiency of the heating capacity Qhp to the required heating capacity Qtgt by heating the auxiliary heating device.

[0012] The method for operating the vehicle air conditioning device of the invention according to claim 1 is also characterized in that the heating capacity Qhp is a heating capacity in non-icing conditions QhpNI, which is to be generated by the heating element when the external heat exchanger is not iced up, and a deficiency of the heating capacity in non-icing conditions QhpNI to the required heating capacity Qtgt is compensated for by heating the auxiliary heating device.

[0013] The method for operating the vehicle air conditioning device of the invention according to claim 1 is further characterized in that, in the invention, the control device stops the compressor and controls the auxiliary heating device according to the required heating capacity Qtgt if the actual heating capacity Qhpr, which is actually to be generated by the heating element, is less than the heating capacity in non-icing conditions QhpNI, and a difference between the heating capacity in non-icing conditions QhpNI and the actual heating capacity Qhpr is greater than a predetermined value.

[0014] The method for operating the vehicle air conditioning device of the invention according to claim 2 is characterized in that, in the invention described above, the control device adds a difference between the heating capacity in non-icing conditions QhpNI and an actual heating capacity Qhpr that is actually to be generated by the heating element in order to carry out heating by the auxiliary heating device when the actual heating capacity Qhpr is less than the heating capacity in non-icing conditions QhpNI.

[0015] The method for operating the vehicle air conditioning device of the invention according to claim 3 is characterized in that, in the invention according to claim 1 or claim 2, the control device calculates the actual heating capacity Qhpr on the basis of one of those indices that specify a temperature of the air flowing out of the radiator and a volume of the air passing through the radiator, or a combination of the indices, and indices that specify a specific heat of the air flowing into the radiator and a density of the air.

[0016] The method for operating the vehicle air conditioning device of the invention according to claim 4 is characterized in that, in the inventions according to claims 1 to 3, the control device calculates the required heating capacity Qtgt on the basis of one of the indices that specify a temperature of the air flowing into the radiator, a temperature of the air flowing out of the radiator and a volume of air passing through the radiator, or any combination of the indices, and indices that specify a specific heat of the air flowing into the radiator and a density of the air, and calculates the heating capacity in non-icing conditions QhpNI on the basis of one of the indices that specify an outside air temperature, a refrigerant flow rate, an air volume in the airflow duct, a velocity, a volume of air passing through the outside heat exchanger, an electrical voltage of an outside blower,that drives the air through the external heat exchanger, a temperature of the heat absorber, a speed of the compressor, a refrigerant pressure at an outlet of the radiator, a refrigerant temperature at the outlet of the radiator, a refrigerant pressure at an inlet of the radiator and a refrigerant temperature at the inlet of the radiator, or any combination of the indices.

[0017] The method for operating the vehicle air conditioning device of the invention according to claim 5 is characterized in that, in the respective inventions described above, the heating element is arranged outside the airflow duct, and the auxiliary heating device is formed by a heating medium circulation circuit with a heating medium / refrigerant heat exchanger to carry out a heat exchange with the heating element, a heating medium / air heat exchanger arranged in the airflow duct, an electric heating device, and a circulation device that circulates the heating medium, which is heated by the heating medium / refrigerant heat exchanger and / or the electric heating device, through the heating medium / air heat exchanger and through the circulation device.

[0018] The method for operating the vehicle air conditioning device of the invention according to claim 6 is characterized in that, in the inventions of claims 1 to 4, the auxiliary heating device is formed by an electric heating device which is arranged in the airflow duct to heat the air which is to be supplied to the vehicle interior.

[0019] The method for operating the vehicle air conditioning device of the invention according to claim 7 is characterized in that, in the inventions according to claims 1 to 4, the heating element is arranged in the airflow duct, and the auxiliary heating device is formed by a heating medium circulation circuit with a heating medium / air heat exchanger arranged in the airflow duct, an electric heating device and a circulation device, and it circulates a heating medium, which is heated by the electric heating device, through the heating medium / air heat exchanger through the circulation device.

[0020] The method for operating the vehicle air conditioning device of the invention according to claim 8 is characterized in that, in the invention described above, the heating medium circulation circuit has a heating medium / refrigerant heat exchanger that collects heat from the refrigerant that has passed through the heating element.

[0021] The method for operating the vehicle air conditioning device of the invention according to claim 9 is characterized in that, in the invention according to claim 7 or claim 8, the control device performs a preliminary operation to start heating through the heating medium circulation circuit when the heating capacity through the radiator is not insufficient, but a difference between a heating capacity in non-icing conditions QhpNI, which is to be generated by the radiator when the external heat exchanger is not iced up, and a required heating capacity Qtgt, which is the heating capacity required for the radiator, is reduced to a predetermined value.

[0022] The method for operating the vehicle air conditioning device of the invention according to claim 10 is characterized in that, in the invention described above, the control device reduces the heating capacity through the radiator as much as the heating through the heating medium circulation circuit during the execution of the preliminary operation.

[0023] The method for operating the vehicle air conditioning device of the invention according to claim 11 is characterized in that, in the invention according to claim 9 or claim 10, the control device limits the quantity of the heating medium to be circulated through the heating medium / air heat exchanger when the temperature of the heating medium flowing through the heating medium circulation circuit is less than a predetermined value during the execution of the preliminary operation.

[0024] The method for operating the vehicle air conditioning device of the invention according to claim 12 is characterized in that, in the inventions according to claim 6 or claim 11, the electric heating device or the heating medium / air heat exchanger is arranged on a downstream side of the heating element in relation to the flow of air in the airflow channel.

[0025] The method for operating the vehicle air conditioning device of the invention according to claim 13 is characterized in that, in the inventions according to claims 6 to 11, the electric heating device or the heating medium / air heat exchanger is arranged on an upstream side of the heating element in relation to the flow of air in the airflow channel. ADVANTAGEOUS EFFECT OF THE INVENTION

[0026] According to the present invention, a vehicle air conditioning device includes a compressor that compresses a refrigerant, an airflow duct through which air flows to be supplied to a vehicle interior, a heater that causes the refrigerant to radiate heat to heat the air supplied from the airflow duct to the vehicle interior, a heat absorber that causes the refrigerant to absorb heat to cool the air supplied from the airflow duct to the vehicle interior, an external heat exchanger arranged outside the vehicle interior to cause the refrigerant to radiate or absorb heat, and a control device, wherein this control device is configured to execute at least one heating mode in which the refrigerant discharged from the compressor radiates heat into the heater and the refrigerant from which the heat was radiated,The system is designed so that the air supply is heated and then absorbed by the external heat exchanger. An auxiliary heating device is provided to heat the air supplied from the airflow duct to the vehicle interior. The control unit activates the auxiliary heating device when the heating capacity of the radiator becomes insufficient. Therefore, if the heating capacity of the radiator becomes insufficient, as in the case of icing of the external heat exchanger or similar issues, the auxiliary heating device can heat the air supplied to the vehicle interior to compensate for the reduced heating capacity. This ensures comfortable heating of the vehicle interior and prevents icing of the external heat exchanger.

[0027] Additionally, the auxiliary heating system activates when the heating capacity of the radiator is insufficient, thus minimizing any reduction in efficiency due to the auxiliary heating system. Consequently, particularly in electric vehicles, this effectively prevents the disadvantage of reduced range.

[0028] As in the invention according to claim 1, the control device in this case compares a required heating capacity Qtgt, which is the heating capacity required by the radiator, with a heating capacity Qhp to be generated by the radiator, and it compensates for a deficiency of the heating capacity Qhp with respect to the required heating capacity Qtgt by heating the auxiliary heating device, so that comfortable heating of the vehicle interior and prevention of the deterioration of efficiency can be effectively achieved.

[0029] As in the invention according to claim 1, for example, the heating capacity Qhp is defined as a heating capacity in non-icing conditions QhpNI that is to be generated by the heater when the external heat exchanger is not iced up, and a deficiency of the heating capacity in non-icing conditions QhpNI with respect to the required heating capacity Qtgt is compensated for by heating the auxiliary heating device, so that it can be detected whether the heating capacity of the heater is becoming insufficient or not, in a phase before the external heat exchanger ices up, whereby heating by the auxiliary heating device can be started quickly, and the heating of the vehicle interior can be realized even more comfortably.

[0030] As in the invention according to claim 1, the control device additionally stops the compressor and controls the auxiliary heating device according to the required heating capacity Qtgt if the actual heating capacity Qhpr to be generated by the heater is less than the heating capacity in non-icing conditions QhpNI, and the difference between the heating capacity in non-icing conditions QhpNI and the actual heating capacity Qhpr is greater than a predetermined value. In this case, the degree of icing progress on the external heat exchanger can be detected, and heating can only be activated for heating the vehicle interior by the auxiliary heating device if the icing progresses adversely. Consequently, it is possible to continuously heat the vehicle interior by the auxiliary heating device while preventing further icing of the external heat exchanger or promoting the melting of the ice.

[0031] As in the invention according to claim 2, the control device adds a difference between the heating capacity in non-icing conditions (QhpNI) and the actual heating capacity Qhpr that the radiator actually needs to generate in order to perform heating by the auxiliary heating device when the actual heating capacity Qhpr is less than the heating capacity in non-icing conditions QhpNI. If, in this case, the outdoor heat exchanger is iced up and the actual heating capacity Qhpr is less than the heating capacity in non-icing conditions QhpNI, the reduction can be compensated for by the auxiliary heating device, and comfort can be further improved.

[0032] As in the invention according to claim 3, the control device in this case calculates the actual heating capacity Qhpr based on one of the indices that specify a temperature of the air flowing out of the radiator and a volume of the air passing through the radiator, or a combination of the indices, and indices that specify the specific heat of the air flowing into the radiator and a density of the air. As in the invention according to claim 4, the control device calculates the required heating capacity Qtgt based on one of the indices that specify a temperature of the air flowing into the radiator, a temperature of the air flowing out of the radiator, and a volume of the air passing through the radiator, or any combination of the indices, and indices that specify a specific heat of the air flowing into the radiator and a density of the air.and it calculates the heating capacity in non-icing conditions QhpNI based on one of the indices that specify an outside air temperature, a refrigerant flow rate, an air volume in the airflow duct, a velocity, a volume of air passing through the outside heat exchanger, an electrical voltage of an outside fan that drives the air through the outside heat exchanger, a temperature of the heat absorber, a speed of the compressor, a refrigerant pressure at a radiator outlet, a refrigerant temperature at a radiator outlet, a refrigerant pressure at a radiator inlet, and a refrigerant temperature at the radiator inlet, or any combination of the indices. Consequently, it is possible to determine the heating capacity by the radiator and the heating by the auxiliary heating device even more precisely due to the lack of heating capacity.

[0033] It should be noted that, as in the invention according to claim 5, the heating element is arranged outside the airflow duct, and the auxiliary heating device is formed by a heating medium circulation circuit with a heating medium / refrigerant heat exchanger to effect heat exchange with the heating element, a heating medium / air heat exchanger arranged in the airflow duct, an electric heating device, and a circulation device that circulates a heating medium, heated by the heating medium / refrigerant heat exchanger and / or the electric heating device, through the heating medium / air heat exchanger and through the circulation device. In this case, electrically safer heating of the vehicle interior can be achieved.However, as in the invention according to claim 6, the auxiliary heating device can be formed by an electric heating device arranged in the airflow duct to heat the air that is to be supplied to the vehicle interior.

[0034] As in the invention according to claim 7, the heating element is additionally arranged in the airflow duct, and the auxiliary heating device is formed by a heating medium circulation circuit with a heating medium / air heat exchanger arranged in the airflow duct, an electric heating device, and a circulation device, and it circulates a heating medium, which is heated by the electric heating device, through the heating medium / air heat exchanger and through the circulation device. In this case as well, electrical safety is improved.

[0035] As in the invention according to claim 8, a heating medium / refrigerant heat exchanger is additionally arranged in the heating medium circulation circuit, which collects the heat from the refrigerant that has passed through the radiator, whereby the heat that the refrigerant has released from the radiator is collected by the heating medium that flows in the heating medium circulation circuit, so that it is conveyed to the heating medium / air heat exchanger, so that it is possible to support the heating even more effectively.

[0036] In the case of the heating medium circulation circuit described above, the control device also performs a preliminary operation, as in the invention according to claim 9, to initiate heating through the heating medium circulation circuit when the heating capacity of the radiator is not insufficient, but the difference between the heating capacity QhpNI, which is to be generated by the radiator when the external heat exchanger is not iced, and the required heating capacity Qtgt, which is the heating capacity required from the radiator, is reduced to a predetermined value. If, in this case, the insufficient heating capacity of the radiator is predicted, it is possible to preheat the heating medium in the heating medium circulation circuit and to quickly compensate for the heating capacity using the heating medium circulation circuit.

[0037] As in the invention according to claim 10, in this case the control device additionally reduces the heating capacity through the radiator as much as the heating through the heating medium circulation circuit during the execution of the preliminary operation, and in this case it is possible to eliminate the disadvantage that the heating capacity improves more than necessary during the preliminary operation of the heating medium circulation circuit.

[0038] As in the invention according to claim 11, the control device furthermore limits the amount of heating medium to circulate through the heating medium / air heat exchanger when the temperature of the heating medium flowing through the heating medium circulation circuit is lower than a predetermined value during preliminary operation. While circulation to the heating medium / air heat exchanger is prevented in situations where the temperature of the heating medium in the heating medium circulation circuit remains low, and a temperature drop in the air supplied to the vehicle interior is prevented, a temperature increase of the heating medium is consequently supported. Furthermore, if the heating capacity of the heater becomes insufficient, the air in the airflow duct through the heating medium / air heat exchanger can be rapidly heated to provide the necessary heating.

[0039] If, in this case, the electric heating device or the heating medium / air heat exchanger is arranged on a downstream side of the radiator relative to the airflow in the airflow duct as in the invention according to claim 12, the air heated by the electric heating device or the heating medium / air heat exchanger does not flow into the radiator, and a deterioration of operating efficiency due to a deterioration of the heat exchange function in the radiator can be prevented, as in a case where the electric heating device or the heating medium / air heat exchanger is arranged on an upstream side.

[0040] If the heating medium / air heat exchanger is additionally arranged on the downstream side of the heater, there is a risk that the temperature of the air to be supplied to the vehicle interior will drop in an initial phase after the excitation of the electric heating device has started or in the situation in which the temperature of the heating medium in the heating medium circulation circuit is still low, but the control is implemented as in the invention described above according to claim 14, so that the risk can be eliminated.

[0041] Conversely, if the electric heating device or the heating medium / air heat exchanger is arranged on the upstream side of the heating element with respect to the airflow in the airflow duct, as in the invention according to claim 13, the deterioration of the operating efficiency is feared, as described above. However, this problem does not occur during the start of the excitation of the electric heating device or due to the low temperature of the heating medium in the heating medium circulation circuit. Furthermore, coordinated heating with the heating element is easily achieved, and such preliminary operation as described above is not required. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a structural view of a vehicle air conditioning device of an embodiment to which the present invention is applied; Fig. Figure 2 shows an enlarged view of an airflow duct section of the Fig. 1; Fig. Figure 3 shows a block diagram of an electrical circuit of a control device for the vehicle air conditioning system. Fig. 1; Fig. Figure 4 shows a flowchart to explain the operation of the control device of the vehicle air conditioning system. Fig. 1, Fig. Figure 5 shows a diagram of an example for determining whether heating by means of a heating medium circulation circuit of the Fig. 4 to be carried out or not; Fig. Figure 6 shows a diagram to illustrate another embodiment of the operation of the control device of the vehicle air conditioning system. Fig. 1; Fig. Figure 7 shows a flowchart to explain the operation of the control device. Fig. 6; Fig. Figure 8 shows a flowchart to explain another embodiment of the operation of the control device of the vehicle air conditioning system. Fig. 1; Fig. Figure 9 shows a structural view of a vehicle air conditioning device of another embodiment to which the present invention is applied; Fig. Figure 10 shows a structural view of a vehicle air conditioning device of a further embodiment to which the present invention is applied; Fig. Figure 11 shows an enlarged view of an airflow duct section of the Fig. 10; Fig. Figure 12 shows a diagram to illustrate the relationships between the temperatures of the respective components in the Fig. 11; Fig. Figure 13 shows a structural view of a vehicle air conditioning device of a further embodiment to which the present invention is applied; Fig. Figure 14 shows a structural view of a vehicle air conditioning device of a further embodiment to which the present invention is applied; Fig. Figure 15 shows a structural view of a vehicle air conditioning device of a further embodiment to which the present invention is applied; Fig. Figure 16 shows a structural view of a vehicle air conditioning device of a further embodiment to which the present invention is applied; Fig. Figure 17 shows a flowchart to explain the operation of a control device of a vehicle air conditioning system. Fig. 16; Fig. Figure 18 shows a flowchart to explain a further embodiment of the operation of the control device of the vehicle air conditioning system. Fig. 16; and Fig. Figure 19 shows a structural view of a vehicle air conditioning device of a further embodiment to which the present invention is applied. FORM OF EXECUTION OF THE INVENTION

[0042] Exemplary embodiments of the present invention are described in detail below with reference to the drawings.

[0043] The Fig. Figure 1 shows a structural view of a vehicle air conditioning unit 1 from an embodiment of the present invention. The vehicle of the embodiment to which the present invention is applied is an electric vehicle (EV) without a combustion engine. It is driven by an electric motor powered by energy stored in a battery (not shown), and the vehicle air conditioning unit 1 of the present invention is driven by the power of the battery. In the electric vehicle, where heating cannot be achieved using waste heat from the combustion engine, the vehicle air conditioning unit 1 of the embodiment performs heating by means of a heat pump operation using a refrigerant circuit. It also selectively performs various operating modes for dehumidifying and heating, cooling and dehumidifying, cooling, and the like.

[0044] 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 driving, and it goes without saying that it is also applicable to a conventional vehicle that is driven by the engine.

[0045] The vehicle air conditioning device 1 of the exemplary embodiment conditions the air (heating, cooling, dehumidifying and ventilating) in the electric vehicle, and connected sequentially via a refrigerant pipe 13 are an electric compressor 2, which compresses a refrigerant; a radiator 4, which is arranged in an airflow duct 3 of an HVAC unit 10, in which air from the vehicle interior passes through and circulates to cause the high-temperature and high-pressure refrigerant released from the compressor 2 to flow into the interior through a refrigerant pipe 13G and to radiate heat into the vehicle interior; an external expansion valve 6, which is formed by an electric valve that expands and decompresses the refrigerant during heating; and an external heat exchanger 7, which effects a heat exchange between the refrigerant and the outside air to act as the radiator during cooling.and to serve as an evaporator during heating, an internal expansion valve 8, formed by an electric valve that expands and decompresses the refrigerant, a heat absorber 9 arranged in the airflow duct 3 to cause the refrigerant to absorb heat from the interior and exterior of the vehicle during cooling and dehumidification, an evaporation control valve 11 that regulates the evaporation rate in the heat absorber 9, an accumulator 12, and the like, so that a refrigerant circuit R is formed. It should be noted that an external blower 15 is arranged in the external heat exchanger 7. The external blower 15 forces the outside air through the external heat exchanger 7 and causes heat exchange between the outside air and the refrigerant, whereby the outside air also passes through the external heat exchanger 7 when the vehicle is stopped (i.e. a speed VSP is 0 km / h).

[0046] Additionally, the external heat exchanger 7 has a receiving drying section 14 and a subcooling section 16 arranged sequentially on a refrigerant flow-downstream side, with a refrigerant pipe 13A extending from the external heat exchanger 7 being connected to the receiving drying section 14 via a solenoid valve (an open / close valve) 17, which opens during cooling, and an outlet of the subcooling section 16 being connected to the internal expansion valve 8 via a check valve 18. It should be noted that the receiving drying section 14 and the subcooling section 16 structurally form part of the external heat exchanger 7, and one side of the check valve 18 to the internal expansion valve 8 is forward-directed.

[0047] Additionally, a refrigerant pipe 13B is arranged between the check valve 18 and the internal expansion valve 8, which has a heat exchange relationship with a refrigerant pipe 13C extending from the evaporation control valve 11, which is positioned on an outlet side of the heat absorber 9, and both pipes form an internal heat exchanger 19. Consequently, the refrigerant flowing into the internal 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 control valve 11.

[0048] Additionally, the refrigerant pipe 13A, extending from the outdoor heat exchanger 7, is branched, and this branched refrigerant pipe 13D is connected to the refrigerant pipe 13C on the downstream side of the indoor heat exchanger 19 via a solenoid valve (a normally open / closed valve) 21, which is opened during heating. Furthermore, a refrigerant pipe 13E is branched on an outlet side of the radiator 4 upstream of the outdoor expansion valve 6, and this branched refrigerant pipe 13F is connected to the refrigerant pipe 13B on the downstream side of the check valve 18 via a solenoid valve (a normally open / closed valve) 22, which is opened during dehumidification.

[0049] Additionally, a bypass pipe 13J is connected in parallel to the external expansion valve 6, and a solenoid valve (an open / close valve) 20 is arranged in the bypass pipe 13J. In cooling mode, the solenoid valve opens, allowing the refrigerant to flow and bypass the external expansion valve 6. It should be noted that a pipe 13I is arranged between the external expansion valve 6 and the solenoid valve 20, as well as between the external heat exchanger 7 and the external heat exchanger 7.

[0050] Additionally, 9 different suction connections, such as an outside air suction connection and an inside air suction connection, are provided in the airflow channel 3 on the upstream side of the heat absorber (via a suction connection 25 in the Fig. (1 shown), and a suction conversion flap 26 is arranged in the suction port 25 to convert the air to be introduced into the airflow duct 3 into interior air, which is the air inside the vehicle (an interior air recirculation mode), and into exterior air, which is the air outside the vehicle interior (an exterior air intake mode). Furthermore, an interior blower (blower fan) 27 is arranged on a downstream side of the suction conversion flap 26 to supply the introduced interior or exterior air to the airflow duct 3.

[0051] Additionally, reference numeral 23 is in the Fig. 1. A heating medium circulation circuit serves as an auxiliary heating device, arranged in the vehicle air conditioning unit 1 of the exemplary embodiment. The heating medium circulation circuit 23 comprises a circulation pump 30, forming a circulation device, an electric heating medium heater (shown by ECH in the drawing) 35, and a heating medium / air heat exchanger 40, which is arranged in the airflow duct 3 on the downstream side of the heater 4 relative to the airflow in the airflow duct 3. These components are connected sequentially in a ring-like fashion by a heating medium pipe 23A. It should be noted that the heating medium to be circulated in the heating medium circulation circuit 23 can be, for example, water, a refrigerant such as HFO-1234YF, a coolant, or the like.

[0052] 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 / air heat exchanger 40. The heating medium / air heat exchanger 40 of the heating medium circulation circuit 23 is, in fact, a so-called heating core and supplements the heating in the vehicle interior. Thus, the heating medium circulation circuit 23 is utilized, and therefore the electrical safety of a passenger can be improved.

[0053] In the airflow duct 3 on the upstream side of the radiator 4, an air mixing flap 28 is additionally arranged to regulate the flow rate of indoor or outdoor air through the radiator 4. Furthermore, in the airflow duct 3 on the downstream side of the radiator 4, there is an outlet for the footwell, ventilation, or a defroster (via an outlet 29 in the Fig. 1 shown) formed, and in the outlet 29 an outlet changing flap 31 is arranged to carry out a change control for blowing the air out of the corresponding outlet, as mentioned above.

[0054] Next, reference number 32 in the Fig. 3 a control device (ECU) as a control unit formed by a microcomputer, and an input of the control device 32 is with respective outputs from an outside air temperature sensor 33, which detects an outside air temperature of the vehicle, an outside air humidity sensor 34, which detects an outside air humidity, an HVAC suction temperature sensor 36, which detects a temperature of the air to be drawn from the suction port 25 to the airflow duct 3, an inside air temperature sensor 37, which detects a temperature of the air inside the vehicle (the interior air), an inside air humidity sensor 38, which detects a humidity of the air inside the vehicle, an inside air CO2 concentration sensor 39, which detects a carbon dioxide concentration inside the vehicle, an outlet temperature sensor 41, which detects a temperature of the air blown out of the outlet 29 into the vehicle interior, an outlet pressure sensor 42,which detects the pressure of the refrigerant being discharged from compressor 2, an outlet temperature sensor 43 which detects the temperature of the refrigerant being discharged from compressor 2, a suction pressure sensor 44 which detects the refrigerant suction pressure of compressor 2, a radiator temperature sensor 46 which detects the temperature of radiator 4 (the temperature of the air passing through radiator 4 or the temperature of radiator 4 itself), a radiator pressure sensor 47 which detects the refrigerant temperature of radiator 4 (the pressure in radiator 4 or the pressure of the refrigerant that has just flowed out of radiator 4), a heat absorber temperature sensor 48 which detects the temperature of heat absorber 9 (the temperature of the air that has passed through heat absorber 9 or the temperature of heat absorber 9 itself), a heat absorber pressure sensor 49,which detects a refrigerant pressure of the heat absorber 9 (the pressure in the heat absorber 9 or the pressure of the refrigerant that has just flowed out of the heat absorber 9), a solar radiation sensor 51 such as a photosensor system for detecting a solar radiation quantity in the vehicle, a speed sensor 52 for detecting a movement speed of the vehicle (a velocity), an air conditioning control section 53 for setting the change of the predetermined temperature or the operating mode, an outside heat exchanger temperature sensor 54 which detects a temperature of the outside heat exchanger 7 (the temperature of the refrigerant that has just flowed out of the outside heat exchanger 7, or the temperature of the outside heat exchanger 7 itself), and an outside heat exchanger pressure sensor 56 which detects the refrigerant pressure of the outside heat exchanger 7 (the pressure of the refrigerant in the outside heat exchanger 7 or of the refrigerant,(which has just flowed out of the external heat exchanger 7) is recorded.

[0055] In addition, the input of the control device 32 is further connected to various outputs from a temperature sensor 50 of the electric heating medium heating device, which detects a temperature of the electric heating medium heating device 35 of the heating medium circulation circuit 23 (the temperature of the heating medium immediately after it has been heated by the electric heating medium heating device 35, or a temperature of an electric heating device not shown, which is built into the electric heating medium heating device 35), and a temperature sensor 55 of the heating medium / air heat exchanger, which 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).

[0056] On the other hand, a control device 32 is connected to the compressor 2, the external blower 15, the internal blower (the fan) 27, the intake alternation flap 26, the air mixing flap 28, the outlet alternation flap 31, the external expansion valve 6, the internal expansion valve 8, the various solenoid valves 22, 17, 21 and 20, the circulation pump 30, the electric heating medium heater 35 and the evaporation capacity control valve 11. Furthermore, the control device 32 controls these components based on the outputs from the various sensors and the setting entered by the air conditioning control section 53.

[0057] Next, the operation of the vehicle air conditioning unit 1 of the exemplary embodiment with the setup described above will be described. In the exemplary embodiment, the control unit 32 changes between and executes different, broadly categorized operating modes, such as a heating mode, a dehumidification and heating mode, an internal cycle mode, a dehumidification and cooling mode, and a cooling mode. First, the flow of the refrigerant in the respective operating mode will be described. (1) Flow of refrigerant in heating mode

[0058] When the heating mode is selected by the control device 32 or by manual operation of the air conditioning control section 53, the control device 32 opens solenoid valve 21 and closes solenoid valves 17, 22, and 20. Additionally, compressor 2 and the respective fans 15 and 27 are operated, and the air mixing flap 28 is in a state in which the air blown from the internal fan 27 passes through the radiator 4 and the heating medium / air heat exchanger 40. Consequently, the high-temperature, high-pressure refrigerant gas discharged from compressor 2 flows into radiator 4.The air in the airflow duct 3 passes through the radiator 4, and thus the air in the airflow duct 3 is heated by the high-temperature refrigerant in the radiator 4, whereas the refrigerant in the radiator 4 has the heat that is absorbed by the air, and it is cooled to condense and become liquid.

[0059] The refrigerant, liquefied in radiator 4, flows out of radiator 4 and then through refrigerant pipe 13E to reach the external expansion valve 6. The operation and function of the heating medium circulation circuit 23 will be described later. The refrigerant flowing into the external expansion valve 6 expands and then flows into the external heat exchanger 7. The refrigerant flowing into the external heat exchanger 7 evaporates, and the heat is extracted by the outside air passing through it, either by the airflow or by the external fan 15. The refrigerant circuit R thus becomes a heat pump (shown by HP in the drawing).Furthermore, the low-temperature refrigerant exiting the external heat exchanger 7 flows through the refrigerant pipe 13D and the solenoid valve 21 to enter the accumulator 12 via the refrigerant pipe 13C, where a gas / liquid separation occurs. The gaseous refrigerant is then drawn into the compressor 2, and this circulation is repeated. The air heated in the radiator 4 is blown out of the outlet 29 through the heating medium / air heat exchanger 40, thus heating the vehicle interior.

[0060] The control device 32 controls the speed of the compressor 2 based on a high pressure of the refrigerant circuit R, which is detected by the outlet pressure sensor 42 or the radiator pressure sensor 47, and it also controls a valve position of the external expansion valve 6 based on the temperature of the radiator 4, which is detected by the radiator temperature sensor 46, and the refrigerant pressure of the radiator 4, which is detected by the radiator pressure sensor 47, and it controls a degree of subcooling of the refrigerant in the outlet of the radiator 4. (2) Flow of refrigerant in dehumidification and heating mode

[0061] Next, in dehumidification and heating mode, the control device 32 opens the solenoid valve 22 in the heating mode state described above. Consequently, a portion of the condensed refrigerant flowing through the radiator 4 and the refrigerant tube 13E is distributed and flows through the solenoid valve 22 to exit the refrigerant tubes 13F and 13B through the internal heat exchanger 19, reaching the internal expansion valve 8. The refrigerant expands in the internal expansion valve 8 and then flows into the heat absorber 9 to evaporate. Water in the air blown out by the internal fan 27 coagulates and adheres to the heat absorber 9 through heat absorption during this period, thus cooling and dehumidifying the air.

[0062] The refrigerant evaporated in the heat absorber 9 flows through the evaporation 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 so that it is drawn into the compressor 2, with this circulation being repeated. The air dehumidified in the heat absorber 9 is reheated in a process in which it passes through the radiator 4, thus dehumidifying and heating the vehicle interior. The control device 32 controls the speed of the compressor 2 on the basis of the high pressure of the refrigerant circuit R, which is detected by the outlet pressure sensor 42 or the radiator pressure sensor 47, and it also controls the valve position of the external expansion valve 6 on the basis of the temperature of the heat absorber 9, which is detected by the heat absorber temperature sensor 48. (3) Flow of refrigerant in internal cycle mode

[0063] Next, in internal cycle mode, the control device 32 interrupts the external expansion valve 6 in the dehumidification and heating mode state described above (an interruption position), and it also closes the solenoid valve 21. The external expansion valve 6 and the solenoid valve 21 are closed, thus preventing the refrigerant from flowing into and out of the external heat exchanger 7. Consequently, all the condensed refrigerant flowing through the radiator 4 and the refrigerant tube 13E flows through the solenoid valve 22 to the refrigerant tube 13F. Furthermore, the refrigerant flowing through the refrigerant tube 13F flows from the refrigerant tube 13B through the internal heat exchanger 19 to reach the internal expansion valve 8. The refrigerant 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 internal blower 27 coagulates to adhere to the heat absorber 9 through the heat absorption operation during this period, thus cooling and dehumidifying the air.

[0064] The refrigerant evaporated in the heat absorber 9 flows through the evaporation control valve 11, the interior heat exchanger 19, the refrigerant pipe 13C, and the accumulator 12 to be drawn into the compressor 2, with this circulation being repeated. The air dehumidified in the heat absorber 9 is reheated as it passes through the radiator 4, thus dehumidifying and heating the vehicle interior. In this internal cycle, however, the refrigerant circulates between the radiator 4 (heat radiation) and the heat absorber 9 (heat absorption), which are located in the airflow duct 3 on one side of the interior. Therefore, heat is not drawn from the outside air, but rather a heating capacity is utilized to compensate for the power consumed by the compressor 2.The entire amount of refrigerant flows through the heat absorber 9, which performs a dehumidification operation, and thus the dehumidification capacity is high compared to the dehumidification and heating mode described above, but the heating capacity is reduced.

[0065] The control device 32 controls the speed of the compressor 2 based on the temperature of the heat absorber 9 or the high pressure of the refrigerant circuit R described above. The control device 32 selects a lower compressor setpoint speed from compressor setpoint speeds obtained by calculations based on the temperature of the heat absorber 9 or the high pressure in order to control the compressor 2. (4) Flow of refrigerant in dehumidification and cooling mode

[0066] Next, in dehumidification and cooling mode, the control device 32 opens solenoid valve 17 and closes solenoid valves 21, 22, and 20. In addition, compressor 2 and the respective fans 15 and 27 are operated, and the air mixing flap 28 is in the position where the air blown out of the internal fan 27 passes through the radiator 4 and the heating medium / air heat exchanger 40. Consequently, the high-temperature, high-pressure refrigerant gas released from compressor 2 flows into radiator 4. Air passes through radiator 4 in airflow duct 3, and thus the air in airflow duct 3 is heated by the high-temperature refrigerant in radiator 4, while the refrigerant in radiator 4 absorbs heat from the air and is cooled to condense and liquefy.

[0067] The refrigerant flowing out of radiator 4 flows through refrigerant pipe 13E to reach the external expansion valve 6. It then flows through the external expansion valve 6, which is controlled to tend to open, allowing the refrigerant to flow into the external heat exchanger 7. The refrigerant flowing into the external heat exchanger 7 is cooled either by flowing into it or by the outside air passing through the external fan 15, causing it to condense. The refrigerant flowing out of the external heat exchanger 7 exits the refrigerant pipe 13A through the solenoid valve 17 and then flows into the receiving drying section 14 and the subcooling section 16. Here, the refrigerant is subcooled.

[0068] The refrigerant flowing out of the subcooling section 16 of the external heat exchanger 7 flows through the check valve 18 to enter the refrigerant pipe 13B and through the internal heat exchanger 19 to reach the internal expansion valve 8. The refrigerant expands in the internal expansion valve 8 and then flows into the heat absorber 9 to evaporate. The water in the air blown out of the internal fan 27 coagulates and adheres to the heat absorber 9 due to the heat absorption operation during this period, thus cooling and dehumidifying the air.

[0069] The refrigerant evaporated in the heat absorber 9 flows through the evaporation control valve 11, the interior heat exchanger 19, and the refrigerant pipe 13C to reach the accumulator 12, where it is drawn into the compressor 2, with this circulation being repeated. The air, cooled and dehumidified in the heat absorber 9, is reheated as it passes through the heater 4 (the heating capacity is lower than during the initial heating phase), thus dehumidifying and cooling the vehicle interior.The control device 32 controls the speed of the compressor 2 on the basis of the temperature of the heat absorber 9, which is detected by the heat absorber temperature sensor 48, and it also controls the valve position of the external expansion valve 6 on the basis of the high pressure of the refrigerant circuit R described above, and it controls a refrigerant pressure (a radiator pressure PCI) of the radiator 4. (5) Flow of refrigerant in cooling mode

[0070] Next, in cooling mode, the control device 32 opens the solenoid valve 20 in the dehumidification and cooling mode described above (in this case, the external expansion valve 6 can be in any position, including fully open (the valve position is set to an upper limit of the control), and the air mixing flap 28 is in a state where air does not pass through the radiator 4 and the heating medium / air heat exchanger 40). Consequently, the high-temperature, high-pressure refrigerant gas discharged by the compressor 2 flows into the radiator 4. The air in the airflow duct 3 does not pass through the radiator 4; therefore, 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 external expansion valve 6.

[0071] The solenoid valve 20 opens, allowing the refrigerant to bypass the external expansion valve 6 and flow through the bypass pipe 13J into the external heat exchanger 7. The refrigerant is cooled either by flowing through it or by the outside air passing through the external fan 15, causing it to condense and liquefy. The refrigerant exiting the external heat exchanger 7 flows from the refrigerant pipe 13A through the solenoid valve 17 and successively into the receiving drying section 14 and the subcooling section 16. During this process, the refrigerant is subcooled.

[0072] The refrigerant flowing out of the subcooling section 16 of the external heat exchanger 7 flows through the check valve 18 to enter the refrigerant pipe 13B and through the internal heat exchanger 19 to reach the internal expansion valve 8. The refrigerant expands 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 internal fan 27 coagulates and adheres to the heat absorber 9 due to the heat absorption operation during this period, thus cooling the air.

[0073] The refrigerant evaporated in the heat absorber 9 flows through the evaporation control valve 11, the internal heat exchanger 19, and the refrigerant pipe 13C to reach the accumulator 12, where it is drawn into the compressor 2, and this circulation is repeated. 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 control device 32 regulates the speed of the compressor 2 based on the temperature of the heat absorber 9, which is detected by the heat absorber temperature sensor 48. (6) Heating mode and auxiliary heating through the heating medium circulation circuit (auxiliary heating device) in the heating mode

[0074] Next, the control of the compressor 2 and the external expansion valve 6 in the heating mode and the auxiliary heating by the heating medium circulation circuit 23 in the heating mode is described. (6-1) Control of the compressor and the external expansion valve

[0075] The control device 32 calculates a target outlet temperature TAO from the following equation (I). The target outlet temperature TAO is a setpoint for the temperature of the air that is 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 inside the vehicle, set by the air conditioning control section 53, Tin is the temperature of the air inside the vehicle, detected by the interior air temperature sensor 37, K is a coefficient, and Tbal is an equilibrium value calculated from the predetermined temperature Tset, a solar irradiance amount SUN detected by the solar irradiance sensor 51, and an outside air temperature Tam detected by the outside air temperature sensor 33. Furthermore, the setpoint output temperature TAO is generally higher the lower the outside air temperature Tam, and the setpoint output temperature TAO is lower the higher the outside air temperature Tam.

[0076] The control device 32 calculates a target radiator temperature TCO from the target outlet temperature TAO, and next it calculates a target radiator pressure PCO based on the target radiator temperature TCO. Furthermore, based on the target radiator pressure PCO and a refrigerant pressure (a radiator pressure) Pci of the radiator 4, which is detected by the radiator pressure sensor 47, the control device 32 calculates a speed Nc of the compressor 2, and it operates the compressor 2 at the speed Nc. In other words, the control device 32 controls the refrigerant pressure Pci of the radiator 4 according to the speed Nc of the compressor 2.

[0077] Additionally, the control device 32 calculates a target radiator subcooling degree TGSC of radiator 4 based on the target outlet temperature TAO. Furthermore, the control device 32 calculates a subcooling degree (a radiator subcooling degree SC) of the refrigerant in radiator 4 based on the radiator pressure Pci and the temperature (a radiator temperature Tci) of radiator 4, which is detected by the radiator temperature sensor 46. Finally, based on the radiator subcooling degree SC and the target radiator subcooling degree TGSC, the control device calculates a target valve position of the external expansion valve 6 (a target external expansion valve position TGECCV). The control device 32 then controls the valve position of the external expansion valve 6 according to the target external expansion valve position TGECCV.

[0078] The control device 32 performs the calculation in such a way that the target radiator subcooling level TGSC increases when the target outlet temperature TAO increases. However, the present invention is not limited to this example, and the control device can perform the calculation based on a difference (a capacity difference) between a subsequently described required heating capacity Qtgt and a heating capacity Qhp (QhpNI) 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 reduces the target radiator subcooling level TGSC when the capacity difference decreases, the pressure difference decreases, the air volume of the internal blower 27 decreases, or the radiator pressure Pci decreases. (6-2) 1. Control of the heating medium circulation circuit

[0079] If the control device 32 determines that the heating capacity through the radiator 4 is becoming insufficient in this heating mode, the control device additionally excites the electric heating medium heating device 35 to generate heat, and it actuates the circulation pump 30, thereby carrying out the heating through the heating medium circulation circuit 23.

[0080] When the circulation pump 30 of the heating medium circulation circuit 23 is activated and the electric heating medium heating device 35 is energized, the heating medium (the high-temperature heating medium) heated by the electric heating medium heating device 35 as described above is circulated through the heating medium / air heat exchanger 40, thus heating the air passing through the heating element 4 of the airflow duct 3. Fig. Figure 2 shows the temperatures of the respective components in the airflow duct 3 during this period. In this drawing, Ga is the air mass volume of the air flowing into the airflow duct 3, Te is the temperature of the heat absorber 9 as 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 the opening of the air mixing flap 28, THhp is the temperature of the air that has passed through the radiator 4 as detected by the radiator temperature sensor 46 (i.e.,The radiator temperature Tci), and TH is the temperature of the air that has passed through the heating medium / air heat exchanger 40, as detected by the temperature sensor 55 of the heating medium / air heat exchanger, and in heating mode, the setpoint temperature of the air flowing out of the heating medium / air heat exchanger 40 and blown out of the outlet 29 is the radiator setpoint temperature TCO. It should be noted that TH = THp applies when the heating medium circulation circuit 23 is not in operation.

[0081] Next, the control of the heating medium circulation circuit 23 in the heating mode described above will be carried out with reference to the Fig. 4 and Fig. 5 described. The control device 32 calculates the required heating capacity Qtgt, which is the heating capacity required for the radiator 4, and the non-icing heating capacity (QhpNI) as the heating capacity Qhp that can be generated by the radiator 4, using equations (II) and (III). The non-icing heating capacity QhpNI is a predicted value of the heating capacity that can be generated by the radiator 4 at the outside air temperature Tam during this period when the outdoor heat exchanger 7 is not iced up (at non-icing) (i.e., an estimated maximum heating capacity of the heat pump). Qtgt=(TCO−Te)×Cpa×ρ×Qair QhpNI=f(Tam,Nc,BLV,VSP,FANVout,Te) where Te is the temperature of the heat absorber 9, which is detected by the heat absorber temperature sensor 48, Cpa is a specific heat [kj / kg·K] of the air flowing into the radiator 4, ρ is a density (a specific volume) [kg / m³]3 ] of the air that flows into radiator 4, Qair a volume [m³ 3 / h] is the air passing through the radiator 4 (estimated from an electrical blower voltage BLV of the internal blower 27 or the like), VSP is the velocity obtained from the velocity sensor 52, and FANVout is an electrical voltage of the external blower 15.

[0082] It should be noted that in equation (II) the temperature of the air flowing into radiator 4 or the temperature of the air flowing out of radiator 4 can be used instead of or in addition to Qair.

[0083] Additionally, the speed Nc of compressor 2 in equation (III) is an example of an index indicating a refrigerant flow rate, the electrical blower voltage BLV is an example of an index indicating the air volume in the airflow duct 3, and the heating capacity QhpNI is calculated from a function of these indices. Additionally, the electrical voltage FANVout of the external blower 15 is an index indicating an air flow volume of the external heat exchanger 7 when the vehicle is stopped (VSP is zero). Furthermore, QhpNI can be calculated from these indices and one each from the outlet refrigerant pressure of radiator 4, the outlet refrigerant temperature of radiator 4, the inlet refrigerant pressure of radiator 4, and the inlet refrigerant temperature of radiator 4, or from any combination thereof.

[0084] The control device 32 reads data from the respective sensor at step S1 in the flowchart of the Fig. 4, and it calculates the required heating capacity Qtgt using equation (II) described above at step S2. Next, the control device calculates the heating capacity QhpNI (an estimated value) when the external heat exchanger 7 is not iced up, using equation (III) described above at step S3, and it determines at step S4 whether the required heating capacity Qtgt is greater than the heating capacity QhpNI or not.

[0085] A diagonal line in the Fig. Figure 5 shows a boundary line of the heating capacity in non-icing conditions QhpNI through the radiator 4 when the outdoor heat exchanger 7 is not iced up; the abscissa indicates the outdoor air temperature Tam, and the ordinate indicates the heating capacity. If in the Fig. 5. If the required heating capacity Qtgt (the limit of the heating capacity) is less than the heating capacity in non-icing state QhpNI, i.e., if the heating capacity in non-icing state QhpNI of the radiator 4 is sufficient for the required heating capacity Qtgt, the control device proceeds to step S6, it stops the heating through the heating medium circulation circuit 23 (it stops the circulation pump 30 and does not energize the electric heating medium heating device 35 to stop the ECH), and it operates the compressor 2 and the like of the refrigerant circuit R, so that the radiator 4 generates the required heating capacity Qtgt (TGHP = Qtgt).

[0086] If, on the other hand, in the Fig. 5. If the required heating capacity Qtgt is greater than the limit line (the slanted line) of the heating capacity in non-icing conditions QhpNI, i.e., the heating capacity in non-icing conditions QhpNI of radiator 4 is close to meeting the required heating capacity Qtgt, the control device advances from step S4 to step S5, thereby executing coordinated operation of radiator 4 of the refrigerant circuit R and the heating medium / air heat exchanger 40 (ECH) of the heating medium circulation circuit 23. Specifically, the control device 32 operates the circulation pump 30 of the heating medium circulation circuit 23 and energizes the electric heating medium heater 35, thus initiating heating through the heating medium / air heat exchanger 40 in addition to heating through radiator 4 of the refrigerant circuit R.

[0087] The control device 32 regulates the excitation of the electric heating element 35 and the operation of the circulation pump 30 such that the required heating capacity TGQech through the heating element circulation circuit 23 equals the required heating capacity Qtgt minus the heating capacity in non-icing conditions QhpNI, based on readings from the temperature sensor 50 of the electric heating element and the temperature sensor 55 of the heating element / air heat exchanger. Specifically, the control device 32 compensates for the heating capacity deficit in non-icing conditions QhpNI with respect to the required heating capacity Qtgt by heating the heating element / air heat exchanger 40 of the heating element circulation circuit 23. Consequently, comfortable heating of the vehicle interior can be achieved, and icing of the external heat exchanger 7 can be prevented.

[0088] Additionally, heating is carried out by the heating medium / air heat exchanger 40 of the heating medium circulation circuit 23 in a situation where the heating capacity of the radiator 4 becomes limited, thus minimizing any reduction in efficiency caused by the operation of the heating medium circulation circuit 23. Consequently, in an electric vehicle such as the embodiment in question, it is possible to effectively prevent the disadvantage of reduced range.

[0089] Furthermore, the control device 32 compares the required heating capacity Qtgt with the heating capacity in non-icing conditions QhpNI, and compensates for any shortfall in heating capacity QhpNI with respect to the required heating capacity Qtgt by heating the heating medium circulation circuit 23. Therefore, comfortable heating of the vehicle interior and prevention of efficiency deterioration can be effectively achieved. In addition, it can detect whether the heating capacity Qhp of the radiator 4 is insufficient in the period before the external heat exchanger 7 freezes, allowing heating via the heating medium circulation circuit 23 to be initiated quickly, thus further enhancing the comfort of the vehicle interior. (6-3) 2. Control of the heating medium circulation circuit

[0090] Next, another embodiment of the control of the heating medium circulation circuit 23 by the control device 32 will be described with reference to the Fig. 6 and Fig. 7 described. As described above in the heating mode, the refrigerant evaporates in the outdoor heat exchanger 7, and heat is absorbed from the outside air. Therefore, especially in an environment with low outside air temperatures, the water in the outside air adheres to the outdoor heat exchanger 7 as ice and accumulates.

[0091] If the external heat exchanger 7 is iced up, the heat exchange (heat absorption) between the heat exchanger and the outside air is disrupted, and thus the heating capacity Qhp that can actually be generated by the radiator 4, i.e., an actual heating capacity Qhpr, is less than the heating capacity when unfrosted QhpNI (HP estimated heating capacity), as described above. The control device 32 calculates the actual heating capacity Qhpr using equation (IV). Qhpr=(THhp−Te)×Cpa×ρ×Qair where THhp is the temperature of the air passing through the radiator 4, which is detected by the radiator temperature sensor 46 described above (i.e. the radiator temperature Tci).

[0092] This shows the Fig. 6. Relationships between the actual heating capacity Qhpr, the heating capacity when not iced up QhpNI, and the required heating capacity Qtgt. When the external heat exchanger 7 is not iced up, Qhpr is approximately equal to QhpNI, but when the external heat exchanger 7 is iced up, Qhpr decreases. Therefore, the icing on the external heat exchanger 7 can be determined by determining whether a difference (QhpNI - Qhpr) between the heating capacity when not iced up QhpNI and the actual heating capacity Qhpr is a predetermined value (an icing determination threshold) or greater, as described in the Fig. 6(a) is shown.

[0093] It should be noted that it can be determined that the external heat exchanger 7 is iced up by additionally determining whether the rate of reduction of the actual heating capacity Qhpr is a certain value or greater, whether the speed of the compressor 2 increases or not, whether the temperature of the radiator 4 drops or not, or the like, as described in the Fig. 6(b) is shown. In this embodiment, however, the icing is determined by the method described above under (a).

[0094] Additionally, the actual heating capacity Qhpr is less than the heating capacity in non-icing conditions (QhpNI). Even if the excitation of the electric heating medium heating device 35 and the operation of the circulation pump 30 are carried out according to the required heating capacity TGQech by the heating medium circulation circuit 23 = the required heating capacity Qtgt - the heating capacity in non-icing conditions QhpNI (a hatched section in the Fig. 6) as in the embodiment described above ( Fig. 4) are controlled, therefore the wealth will actually be detrimentally reduced by (QhpNI-Qhpr), as indicated by dashed lines in the Fig. Figure 6 is shown. In this embodiment, the control device 32 thus corrects the deficiency in order to control the heating medium circulation circuit 23.

[0095] The control device 32 reads data from the respective sensor at step S7 in a flowchart of the Fig. 7, and it calculates the required heating capacity Qtgt using equation (II) described above at step S8 in the same manner as described above. Next, the control device calculates the heating capacity QhpNI (an estimated value) when the external heat exchanger 7 is not iced up, using equation (III) described above at step S9, and it first determines in a similar manner at step S10 whether the required heating capacity Qtgt is greater than the heating capacity QhpNI or not.

[0096] Furthermore, if the heating capacity of the radiator 4 in non-icing conditions (QhpNI) is sufficient for the required heating capacity Qtgt, the control device proceeds to step S15, it stops the heating through the heating medium circulation circuit 23 (it stops the circulation pump 30 and it does not energize the electric heating medium heating device 35 to stop ECH), and it operates the compressor 2 and the like of the refrigerant circuit R, so that the radiator 4 generates the required heating capacity Qtgt (TGHP = Qtgt).

[0097] If, on the other hand, the heating capacity of radiator 4 under non-icing conditions, QhpNI, falls short of the required heating capacity, Qtgt, the control device proceeds from step S10 to step S11 and calculates the actual heating capacity, Qhpr, using equation (IV) described above. Furthermore, in step S12, it is determined whether the difference (QhpNI - Qhpr) between the heating capacity under non-icing conditions, QhpNI, and the actual heating capacity, Qhpr, is less than a predetermined value A. The respective heating capacities are calculated using equations (II) to (IV) described above, thus enabling even more precise control of the heating capacity provided by radiator 4 and the heating by the heating medium circulation circuit 23 in response to capacity deficiencies.It should be noted that the predetermined value A is a value for determining a state in which the external heat exchanger 7 is iced up, but the icing does not progress too far, and the value can be the icing determination threshold described above or a different value.

[0098] Furthermore, if the difference QhpNI - Qhpr is less than the predetermined value A, the control device 32 determines that the icing of the external heat exchanger 7 does not progress in order to advance from step S12 to step S13, thereby enabling coordinated operation of the radiator 4 of the refrigerant circuit R and the heating medium / air heat exchanger 40 (ECH) of the heating medium circulation circuit 23. Specifically, the control device 32 operates the circulation pump 30 of the heating medium circulation circuit 23 and energizes the electric heating medium heater 35, thus initiating heating by the heating medium / air heat exchanger 40 in addition to heating by the radiator 4 of the refrigerant circuit R.

[0099] The control device 32 controls the excitation of the electric heating medium heater 35 and the operation of the circulation pump 30 such that the required heating capacity TGQech through the heating medium circulation circuit 23 = the required heating capacity Qtgt - the heating capacity in non-icing conditions QhpNI + ΔQhp based on the output of the temperature sensor 50 of the electric heating medium heater or the temperature sensor 55 of the heating medium / air heat exchanger. This ΔQhp is the difference between the heating capacity in non-icing conditions QhpNI and the actual heating capacity Qhpr (ΔQhp = QhpNI - Qhpr).

[0100] In this embodiment, the control device 32 compensates for the lack of heating capacity in non-icing conditions QhpNI with respect to the required heating capacity Qtgt by heating the heating medium / air heat exchanger 40 of the heating medium circulation circuit 23, and it adds the difference ΔQhp between the heating capacity in non-icing conditions QhpNI and the actual heating capacity Qhpr in order to carry out heating through the heating medium / air heat exchanger 40 of the heating medium circulation circuit 23 when the actual heating capacity Qhpr to be generated in the heating element 4 is less than the heating capacity in non-icing conditions QhpNI. If the external heat exchanger 7 is iced up and the actual heating capacity Qhpr to be generated by the radiator 4 is less than the heating capacity when unfrosted QhpNI, the reduction can consequently be compensated for by the heating medium circulation circuit 23, and comfort can be further improved.

[0101] It should be noted that if the difference QhpNI-Qhpr is the predetermined value A or greater at step S12 in the Fig. 7, the control device 32 determines that the icing of the external heat exchanger 7 does not progress in order to proceed from step S12 to step S14, stops the compressor 2 of the refrigerant circuit R (HP stop), and operates the electric heating medium heating device 35 and the circulation pump 30 so that the heating medium / air heat exchanger 40 generates the required heating capacity Qtgt (TGQech = Qtgt).

[0102] As described above, if the degree of icing on the external heat exchanger 7 is detected and the icing progresses adversely, the vehicle interior heating changes to heating only via the heating medium / air heat exchanger 40 of the heating medium circulation circuit 23. Therefore, it is possible to continuously heat the vehicle interior via the heating medium circulation circuit 23 while preventing further icing of the external heat exchanger 7 or promoting the melting of the ice. (6-4) 3. Control of the heating medium circulation circuit

[0103] Next, another embodiment of the control of the heating medium circulation circuit 23 by the control device 32 will be described with reference to the Fig. As described in section 8, the heating medium circulation circuit 23, acting as an auxiliary heating device in this case, circulates the heating medium (the high-temperature heating medium) heated by the electric heating medium heater 35 through the heating medium / air heat exchanger 40 via the circulation pump 30. This circulates the air in the airflow duct 3, which has passed through the radiator 4. The time required to heat the heating medium (the high-temperature heating medium) to a suitable temperature for heating is thus necessary. Therefore, in this embodiment, the control device 32 performs a preliminary operation of the heating medium circulation circuit 23 in one phase before the heating capacity of the radiator 4 (the heating capacity in non-icing conditions, QhpNI) becomes insufficient.

[0104] The Fig. Figure 8 shows the control of the control device 32 in such a case, and steps designated by the same reference numerals are the same as the steps in the Fig. 7. In this embodiment, an area is shown that is defined by a dashed line X in the Fig. Figure 8 shows the preliminary operation of the heating medium circulation circuit 23, which is the Fig. 7 is added. Consequently, a part is mainly described that differs from the Fig. 7 distinguishes. At step S10, the control device 32 proceeds to step S16 if the heating capacity in non-icing conditions QhpNI of the radiator 4 is sufficient for the required heating capacity Qtgt, and it operates the compressor 2 and the like of the refrigerant circuit R to heat the air to be supplied from the airflow duct 3 into the vehicle interior through the radiator 4 (HP control).

[0105] Next, in step S17, it is determined whether the difference (Qtgt - QhpNI) between the required heating capacity Qtgt and the heating capacity in non-icing conditions QhpNI is less than 0 and greater than a predetermined value B. The predetermined value B is a predetermined negative value with a small absolute value. Specifically, in step S17, the control device 32 determines whether the heating capacity in non-icing conditions QhpNI is greater than or equal to the required heating capacity Qtgt (step S10), and whether the difference is less than the absolute value of B.

[0106] At step S17, if the difference (Qtgt - QhpNI) is less than B, i.e., if the heating capacity in non-icing conditions QhpNI is greater than the required heating capacity Qtgt by the absolute value of B or more, the control device further determines that the heating capacity through the heating element 4 is sufficient, so it proceeds to step S15, heating through the heating medium circulation circuit 23 in the same manner as in the Fig. 7 stops (it stops the circulation pump 30, it does not excite the electric heating medium heating device 35, and it stops ECH), and it operates the compressor 2 and the like of the refrigerant circuit R, so that the radiator 4 generates the required heating capacity Qtgt (TGHP = Qtgt).

[0107] If, on the other hand, the difference (Qtgt - QhpNI) is less than 0 and greater than B at step S17, i.e., if the heating capacity in non-icing conditions QhpNI is greater than the required heating capacity Qtgt, but the difference is reduced and less than the absolute value of B, the control device determines that the preliminary operation of the heating medium circulation circuit 23 is required, so it proceeds to step S18, thereby starting the preliminary operation of the heating medium circulation circuit 23.

[0108] During this preliminary operation, the control device starts the operation of the circulation pump 30 of the heating medium circulation circuit 23 and the excitation of the electric heating medium heater 35, while simultaneously operating the compressor 2 of the refrigerant circuit R and the heating element 4 of the refrigerant circuit R (HP) and the heating medium / air heat exchanger 40 (ECH) of the heating medium circulation circuit 23. However, the control device regulates the excitation of the electric heating medium heater 35 and the operation of the circulation pump 30 such that the required heating capacity TGQech through the heating medium circulation circuit 23 equals the required heating capacity Qtgt minus the heating capacity in non-icing conditions QhpNI. Additionally, the required heating capacity TGQech of the heating medium circulation circuit 23 is set above a predetermined value C, thus preventing a deterioration in the efficiency of the heating medium circulation circuit 23 itself.Consequently, the temperature of the heating medium in the heating medium circulation circuit 23 increases, and if the lack of heating capacity is thus predicted by the radiator 4, it is possible to preheat the heating medium in the heating medium circulation circuit 23, and it is possible to quickly achieve a supplementation of the heating capacity using the heating medium circulation circuit 23.

[0109] Additionally, the heating is increased by the heating medium circulation circuit 23 during preliminary operation, thus reducing the heating capacity of radiator 4, so that the target heating capacity TGHP of radiator 4 is equal to the heating capacity in non-icing conditions QhpNI - TGQech. The compressor 2 and the corresponding components of the refrigerant circuit R are operated, so that radiator 4 generates the capacity QhpNI - TGQech, and finally, the heating capacity of radiator 4 is combined with that of the heating medium / air heat exchanger 40 to achieve the required heating capacity Qtgt. Consequently, it is also possible to eliminate the disadvantage of the heating capacity increasing more than necessary during the preliminary operation of the heating medium circulation circuit 23.

[0110] Next, at step S19, the control device 32 determines whether a temperature (defined by ECH water temperature in the flow diagram of the Fig. 8) of the heating medium passing through the electric heating medium heating device 35 of the heating medium circulation circuit 23, which is detected by the temperature sensor 50 of the electric heating medium heating device, is greater than a predetermined value (a temperature for heating). If the temperature is higher, the control device proceeds to a step S20 to circulate a quantity of the heating medium through the circulation pump 30 (by WP in the flow diagram of the Fig. (shown in Figure 8) to set to a normal amount of heating medium, and if the temperature is a predetermined value or less, the control device proceeds to step S21 to limit and reduce the amount of heating medium to be circulated to the heating medium / air heat exchanger 40 by the circulation pump 30 (by WP water quantity limitation in the flow diagram of the Fig. 8 shown). This control of the amount of heating medium to be circulated is carried out by controlling the speed of the circulation pump 30.

[0111] Thus, the control device 32 limits the amount of heating medium to circulate to the heating medium / air heat exchanger 40 when the temperature of the heating medium flowing through the heating medium circulation circuit 23 is lower than a predetermined value during preliminary operation. While circulation to the heating medium / air heat exchanger 40 is prevented by maintaining a low temperature in the heating medium circulation circuit 23 and thus preventing a temperature drop in the air supplied to the vehicle interior, a temperature increase of the heating medium is promoted. If the heating capacity of the heater 4 becomes insufficient, the air in the airflow duct 3 can be rapidly heated by the heating medium / air heat exchanger 40, enabling heating to be carried out.It should be noted that in the exemplary embodiment, the amount of heating medium to be circulated to the heating medium / air heat exchanger 40 is limited by controlling the speed of the circulation pump 30, but the present invention is not limited to this exemplary embodiment. A bypass route around the heating medium / air heat exchanger 40 can be arranged separately, and all or part of the heating medium can flow through this bypass route while the temperature of the heating medium is low in order to limit the amount of heating medium to be circulated to the heating medium / air heat exchanger 40. (7) Example of construction 1

[0112] Next, the Fig. Figure 9 shows an assembly view of another embodiment of the vehicle air conditioning device 1 of the present invention. In this embodiment, an external heat exchanger 7, a receiving drying section 14, and a subcooling section 16 are not arranged, and a refrigerant pipe 13A extending from the external heat exchanger 7 is connected to a refrigerant pipe 13B via a solenoid valve 17 and a check valve 18. Additionally, a refrigerant pipe 13D branching off from the refrigerant pipe 13A is similarly connected to a refrigerant pipe 13C on a downstream side of an internal heat exchanger 19 via a solenoid valve 21.

[0113] The rest of the structure is similar to the example of the Fig. 1. The present invention is also effective in a vehicle air conditioning device 1 with a refrigerant circuit R, in which the external heat exchanger 7, which does not have the receiving drying section 14 and the subcooling section 16, is used in this way. (8) Example of construction 2

[0114] Next, they will show Fig. 10, Fig. 11 to Fig. 12 Assembly views of a further embodiment of the vehicle air conditioning device 1 of the present invention. It should be noted that a refrigerant circuit R of this embodiment is similar to that in the Fig. 9. Additionally, in this case, a heating medium / air heat exchanger 40 of a heating medium circulation circuit 23 is arranged on an upstream side of a radiator 4 for an airflow of an airflow 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] The Fig. Figure 11 shows temperatures and similar data of the respective components in the airflow channel 3 during this period. Fig. Figure 12 additionally shows relationships between a heating capacity in non-icing conditions QhpNI, a required heating capacity TGQech of the heating medium circulation circuit 23, a required heating capacity Qtgt, a heat absorber temperature Te, a temperature THhp of the air flowing out of the radiator 4, and a radiator setpoint temperature TCO. It should be noted that in this drawing the same components are shown with the same reference symbols as in the Fig. 2 are designated.

[0116] In this case, the heating medium / air heat exchanger 40 is positioned on the upstream side of the radiator 4 in the airflow duct 3, and during operation of the heating medium circulation circuit 23, the air is thus heated by the heating medium / air heat exchanger 40 and then flows into the radiator 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 radiator 4 in this way, and in particular, in this case, no problems arise at all due to a low temperature of a heating medium in the heating medium circulation circuit 23. Consequently, coordinated heating with the radiator 4 is facilitated, and such preliminary operation as described above with reference to the Fig. As described in Figure 8, this is not necessary, but the air passing through the heating medium / air heat exchanger 40 flows disadvantageously into the radiator 4, thus reducing the temperature difference between the air and the radiator 4, which poses a risk of reduced 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 relative to the airflow of the airflow duct 3, as described in the Fig. 1 and Fig. As shown in Figure 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 provided in such a way as to prevent a deterioration of the heat exchange function in the radiator 4 compared to the case where the heating medium / air heat exchanger 40 is arranged on the upstream side of the radiator 4, as shown in the Fig. 10 is shown. (9) Example of construction 3

[0117] Next, the Fig. Figure 13 shows an assembly view of a further embodiment of the vehicle air conditioning device 1 of the present invention. The main components of a refrigerant circuit R and a heating medium circulation circuit 23 of this embodiment are similar to those in the Fig. 1, but a heating medium / refrigerant heat exchanger 70 is arranged in the heating medium circulation circuit 23. The heating medium / refrigerant heat exchanger 70 effects a heat exchange between a heating medium pipe 23A, extending from a circulation pump 30, and a refrigerant pipe 13E, extending from a radiator 4 of the refrigerant circuit R. In the heating medium / refrigerant heat exchanger 70, a heating medium discharged from the circulation pump 30 is exposed to heating by a refrigerant flowing out of the radiator 4. Consequently, heat can be collected from the refrigerant passing through the radiator 4 by the heating medium circulating through the heating medium circulation circuit 23.

[0118] Thus, the heating medium / refrigerant heat exchanger 70 is arranged in the heating medium circulation circuit 23, which collects heat from the refrigerant passing through the radiator 4, and thus the heat that the refrigerant passing through the radiator 4 has is collected by the heating medium flowing in the heating medium circulation circuit 23, and it is conveyed to a heating medium / air heat exchanger 40, so that it is possible to support the heating even more effectively. (10) Assembly example 4

[0119] Next, the Fig. Figure 14 shows a structural view of a further embodiment of the vehicle air conditioning device 1 of the present invention. A refrigerant circuit R and a heating medium circulation circuit 23 of this embodiment are similar to those of the Fig. 13, 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 flap 28 with respect to the airflow of the airflow duct 3. According to this configuration as well, heat contained in a refrigerant discharged from the radiator 4 is collected by a heating medium flowing in the heating medium circulation circuit 23, specifically in a heating medium / refrigerant heat exchanger 70, and is transferred to the heating medium / air heat exchanger 40, thus making it possible to support the heating process even more effectively. (11) Example of construction 5

[0120] Next, the Fig. Figure 15 shows a structural view of a further embodiment of the vehicle air conditioning device 1 of the present invention. The pipe structures of a refrigerant circuit R and a heating medium circulation circuit 23 of this embodiment are essentially the same as those of the Fig. 1, but a radiator 4 is not arranged in the airflow duct 3, and it is arranged outside the airflow duct. Instead, in this case, a heating medium / refrigerant heat exchanger 74 is arranged in a heat exchange relationship within the radiator 4.

[0121] The heating medium / refrigerant 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 airflow duct 3. According to such a setup, heat exchange takes place between a heating medium discharged from the circulation pump 30 and a refrigerant flowing through the heater 4, and the heating medium is heated by the refrigerant, it is next heated by the electric heating medium heater 35 (in a case where the heater is energized to generate heat), and then it radiates heat in a heating medium / air heat exchanger 40, thereby heating air that is to be supplied from the airflow duct 3 into a vehicle interior.

[0122] In the vehicle air conditioning device 1 with such a design, the electric heating medium heating device 35 is also excited to heat the heating medium flowing in the heating medium pipe 23A when the heating capacity through the radiator 4 becomes scarce, so that it is possible to support the heating and to achieve electrically safe heating of the vehicle interior, compared to a case in which the electric heating device is arranged in the airflow duct 3, as will be described later. (12) Example of construction 6

[0123] It should be noted that in the respective embodiments described above, a heating medium circulation circuit 23 is used as an auxiliary heating device, but the auxiliary heating device can be formed by an ordinary electric heating device (e.g. a PTC heating device) 73. Fig. Figure 16 shows an example of assembly according to the Fig. 1 in this case, the Fig. Figure 17 shows an example of a control flow diagram according to the Fig. 4, the Fig. Figure 18 shows an example of a control flow diagram according to the Fig. 7, and the Fig. 19 shows an example of assembly according to the Fig. 9. In the Fig. 16 and Fig. 19 is the heating medium circulation circuit 23 of the Fig. 1 and Fig. 9 in this case is replaced by an electric heating device 73. Additionally, steps S5 and S6 are in the Fig. 4 through steps S5A and S6A in the Fig. 17 replaced, and steps S13-S15 of the Fig. 7 are through steps S13A-S15A of the Fig. 18 replaced, but a target size TGQech is replaced by a required heating capacity TGQeh by the electric heating device 73.

[0124] The remaining structure and control are essentially the same, and a control device 32 controls the excitation of the electric heating device 73 instead of the circulation pump 30 and the electric heating medium heating device 35 of the heating medium circulation circuit 23, in order to supplement the heating capacity of a radiator 4 with heat generated by the electric heating device, in the same manner as described above, so that detailed descriptions are omitted. Thus, air to be supplied to a vehicle interior can be heated by the electric heating device 73, and such a structure is advantageously simplified when compared with the case in which the heating medium circulation circuit 23 is used.

[0125] It goes without saying that the electric heating device 73 is located on an upstream side of a radiator 4 of the Fig. 16 or the Fig. 19 as in the case of the Fig. 10 can be arranged, and in this case there is the effect that it is possible to eliminate the disadvantage that the temperature of the air to be supplied into the vehicle interior is reduced in an initial phase of starting the excitation of the electric heating device 73.

[0126] It should be noted that in the exemplary embodiments the present invention is applied to the vehicle air conditioning device 1, which changes and executes respective operating 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 exemplary embodiments, and it is also effective for a vehicle air conditioning device that only performs the heating mode.

[0127] In addition, the respective numerical values ​​described in the exemplary embodiments described above are not limiting to the design of the refrigerant circuit R, and it need not be said that they can be changed without leaving the scope of the present invention. REFERENCE MARK LIST 1 Vehicle air conditioning unit 2 compressors 3 airflow channel 4 radiators 6 External expansion valve 7 external heat exchangers 8 Internal expansion valve 9 heat absorbers 10 HVAC units 11 Evaporation capacity control valve 12 Accumulator 13, 13A-J Refrigerant pipe 14. Intake drying section 15 outdoor blowers 16 Subcooling section 17 Solenoid valve 18 Check valve 19 internal heat exchangers 20, 21 and 22 solenoid valve 23 Heating medium circulation circuit (auxiliary heating device) 23A Heating medium pipe 25 Suction port 26 Suction change flap 27 Interior blower (blower fan) 28 Air mixing flap 29 Outlet 30 Circulation pump (circulation device) 31 Exhaust change valve 32 Control device (control unit) 33 Outdoor air temperature sensor 34 Outdoor humidity sensor 35 electric heating medium heating device (electric heating device) 36 Suction temperature sensor 37 Indoor air temperature sensor 38 Indoor humidity sensor 39 Indoor air CO2 concentration sensor 40 Heating medium / air heat exchanger 41 Outlet temperature sensor 42 Outlet pressure sensor 43 Outlet temperature sensor 44 Suction pressure sensor 46 Radiator temperature sensor 47 Radiator pressure sensor 48 Heat absorber temperature sensor 49 Heat absorber pressure sensor 50 temperature sensor 51 Sunlight sensor 52 Speed ​​sensor 53 Air conditioning control section 54 Outdoor heat exchanger temperature sensor 55 Temperature sensor 56 External heat exchanger pressure sensor 70 and 74 Heating medium / refrigerant heat exchanger 73 electric heating device R Refrigerant circuit

Claims

[1] Method for operating a vehicle air conditioning device (1) with: a compressor (2) that compresses a refrigerant; an airflow channel (3) through which air flows to supply a vehicle interior; a radiator (4) which causes a refrigerant to radiate heat in order to heat the air which is to be supplied from the airflow duct (3) into the vehicle interior; a heat absorber (9) which causes the refrigerant to absorb heat in order to cool the air which is to be supplied from the airflow duct (3) into the vehicle interior; an external heat exchanger (7) located outside the vehicle interior to cause the refrigerant 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 refrigerant discharged from the compressor (2) radiates heat in the radiator (4) and the refrigerant from which the heat was radiated is expanded and then absorbs heat in the outdoor heat exchanger (7), wherein the vehicle air conditioning device (1) further 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) performs heating through the auxiliary heating device (23) when the heating capacity through the radiator (4) becomes insufficient, wherein the control device (32) compares a required heating capacity (Qtgt), which is the heating capacity required for the radiator (4), with a heating capacity (Qhp) to be generated by the radiator (4), and compensates for a deficiency of the heating capacity (Qhp) with respect to the required heating capacity (Qtgt) by heating the auxiliary heating device (23), wherein the heating capacity (Qhp) is a heating capacity in non-icing conditions (QhpNI) to be generated by the radiator (4) when the external heat exchanger (7) is not iced up, and any deficiency in the heating capacity in non-icing conditions (QhpNI) with respect to the required heating capacity (Qtgt) is compensated for by heating the auxiliary heating device (23), and wherein the control device (32) stops the compressor (2) and controls the auxiliary heating device (23) according to the required heating capacity (Qtgt) if an actual heating capacity (Qhpr) to be generated by the radiator (4) is less than the heating capacity when not icing (QhpNI) and a difference between the heating capacity when not icing (QhpNI) and the actual heating capacity (Qhpr) is greater than a predetermined value. [2] The method for operating a vehicle air conditioning device (1) according to claim 1, wherein the control device (32) adds a difference between the heating capacity when not icing (QhpNI) and an actual heating capacity (Qhpr) to be generated by the heater (4) in order to carry out heating by the auxiliary heating device (23) when the actual heating capacity (Qhpr) is less than the heating capacity when not icing (QhpNI). [3] The method for operating a vehicle air conditioning device (1) according to claim 1 or 2, wherein the control device (32) calculates the actual heating capacity (Qhpr) on the basis of one of those indices that specify a temperature of the air flowing out of the radiator (4) and a volume of the air passing through the radiator (4), or a combination of the indices, and indices that specify a specific heat of the air flowing into the radiator (4) and a density of the air. [4] The method for operating a vehicle air conditioning device (1) according to any one of claims 1 to 3, wherein the control device (32) calculates the required heating capacity (Qtgt) on the basis of one of those indices that specify a temperature of the air flowing into the radiator (4), a temperature of the air flowing out of the radiator (4) and a volume of the air passing through the radiator (4), or any combination of the indices, and indices that specify a specific heat of the air flowing into the radiator (4) and a density of the air, and the heating capacity in non-icing conditions (QhpNI) is calculated on the basis of one of those indices that specify an outside air temperature, a refrigerant flow rate, an air volume in the airflow duct (3), a velocity, a volume of air passing through the outside heat exchanger (7), an electrical voltage of an outside blower (15) driving the air through the outside heat exchanger (7), a temperature of the heat absorber (9), a speed of the compressor (2), a refrigerant pressure at an outlet of the radiator (4), a refrigerant temperature at the outlet of the radiator (4), a refrigerant pressure at an inlet of the radiator (4) and a refrigerant temperature at the inlet of the radiator (4), or any combination of the indices. [5] The method for operating a vehicle air conditioning device (1) according to any one of claims 1 to 4, wherein the heating element (4) is arranged outside the airflow duct (3), and the auxiliary heating device (23) is formed by a heating medium circulation circuit (23), comprising a heating medium / refrigerant heat exchanger (74) for effecting a heat exchange with the heating element (4), a heating medium / air heat exchanger (40) arranged in the airflow duct (3), an electric heating device (35), and a circulation device (30) which circulates a heating medium heated by the heating medium / refrigerant heat exchanger (74) and / or the electric heating device (35) through the heating medium / air heat exchanger (40) through the circulation device (30). [6] The method for operating a vehicle air conditioning device (1) according to any one of claims 1 to 4, wherein the auxiliary heating device (23) is formed by an electric heating device (35) which is arranged in the airflow channel (3) to heat the air which is to be supplied into the vehicle interior. [7] The method for operating a vehicle air conditioning device (1) according to one of claims 1 to 4, wherein the heating element (4) is arranged in the airflow duct (3), and the auxiliary heating device (23) is formed by a heating medium circulation circuit (23), comprising a heating medium / air heat exchanger (40) arranged in the airflow duct (3), an electric heating device (35) and a circulation device (30), and a heating medium which is heated by the electric heating device (35) is circulated through the heating medium / air heat exchanger (40) through the circulation device (30). [8] The method for operating a vehicle air conditioning device (1) according to claim 7, wherein the heating medium circulation circuit (23) has a heating medium / refrigerant heat exchanger (70) which collects heat from the refrigerant that has passed through the heating element (4). [9] The method for operating a vehicle air conditioning device (1) according to claim 7 or 8, wherein the control device (32) performs a preliminary operation to start heating through the heating medium circulation circuit (23) when the heating capacity through the radiator (4) is not insufficient, but a difference between a heating capacity in non-icing conditions (QhpNI) to be generated by the radiator (4) when the external heat exchanger (7) is not iced up and a required heating capacity (Qtgt), which is the heating capacity required for the radiator (4), is reduced to a predetermined value. [10] The method for operating a vehicle air conditioning device (1) according to claim 9, wherein the control device (32) reduces the heating capacity through the radiator (4) as much as the heating through the heating medium circulation circuit (23) during the execution of the preliminary operation. [11] The method for operating a vehicle air conditioning device (1) according to claim 9 or 10, wherein the control device (32) limits an amount of a heating medium to be circulated through the heating medium / air heat exchanger (40) when a temperature of the heating medium flowing through the heating medium circulation circuit (23) is less than a predetermined value during the execution of the preliminary operation. [12] The method for operating a vehicle air conditioning device (1) according to any one of claims 6 to 11, wherein the electric heating device (35) or the heating medium / air heat exchanger (40) is arranged on a downstream side of the heating element (4) to the flow of air in the airflow channel (3). [13] The method for operating a vehicle air conditioning device (1) according to any one of claims 6 to 11, wherein the electric heating device (35) or the heating medium / air heat exchanger (40) is arranged on an upstream side of the heating element (4) to the flow of air in the airflow channel (3).

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