DE112020000828T5 - Vehicle air conditioning - Google Patents

Abstract

A vehicle air conditioning system is provided in which the freezing of a heat sink and at the same time a blow-out temperature that serves as a setpoint can be achieved. It comprises a compressor 2, a heat sink 4, an external expansion valve 6, an external heat exchanger 7, an internal expansion valve 8 and a heat sink 9, at least one dehumidifying heating mode being executed by a control device, with refrigerant released from the compressor 2 at the heat sink 4 heat releases and the refrigerant that has given off heat is branched, with one part absorbing heat after a pressure reduction by means of the internal expansion valve 8 on the heat sink 9, while the other part absorbs heat after a pressure reduction by means of the external expansion valve 6 on the external heat exchanger 7. The control device closes the internal expansion valve 8 completely if the temperature of the heat sink 9 falls below a certain value.

Description

TECHNICAL AREA

The present invention relates to a vehicle air conditioning system of the heat pump type for air conditioning a passenger compartment of a vehicle.

Due to the increasingly obvious environmental problems, hybrid vehicles and electric vehicles have become more widespread in recent years. As an air conditioner suitable for such vehicles, an air conditioner has been developed that includes a compressor that compresses and discharges a refrigerant, a heat sink that is provided in a passenger compartment and effects heat exchange with the refrigerant, a heat sink that is in the Passenger compartment is provided and causes the refrigerant to absorb heat, and comprises an external heat exchanger which is provided outside the passenger compartment and causes the refrigerant to dissipate or absorb heat, and between a heating mode in which refrigerant discharged from the compressor heats to the heat sink and the refrigerant that has given off heat at the heat sink absorbs heat at the external heat exchanger, a dehumidification heating mode in which refrigerant discharged from the compressor gives off heat at the heat sink and the refrigerant that has given off heat at the heat sink to the heat sink and the external heat exchanger Warmth absorbed, a cooling mode in which refrigerant released from the compressor releases heat at the external heat exchanger and absorbs heat at the heat sink, and can switch to a dehumidifying cooling mode in which refrigerant released from the compressor releases heat to the heat sink and the external heat exchanger and heat to the heat sink absorbed.

In this case, an external expansion valve is provided on the external heat exchanger, and in the heating mode and in the dehumidifying heating mode, the refrigerant flowing into the external heat exchanger is pressure-reduced by means of the external expansion valve. In the dehumidification heating mode, the refrigerant that has emerged from the heat sink is branched, with one part experiencing a pressure reduction at the internal expansion valve, flowing into the heat sink and thus causing heat to be absorbed by the refrigerant at the heat sink, while the other part is experiencing a pressure reduction at the external expansion valve, flows into the external heat exchanger to cause heat absorption by the refrigerant (see, for example, Patent Document 1).

LIST OF REFERENCE DOCUMENTS

PATENT DOCUMENTS

Patent Document 1: Japanese Unexamined Patent Application No. 2014-94673

SUMMARY OF THE INVENTION

OBJECT OF THE INVENTION

As the temperature at the heat sink drops sharply in the dehumidifying heating mode described above, the speed of the compressor is reduced in the prior art in order to prevent the heat sink from freezing. However, reducing the speed of the compressor lowers the high pressure, whereby the heat dissipation at the heat sink is reduced and it is no longer possible to reach the target blow-out temperature.

If, on the other hand, the speed of the compressor is maintained in order to reach the target blow-out temperature, the heat sink freezes, resulting in the problem that the amount of air blown into the passenger compartment decreases.

The present invention was made to solve these technical problems of the prior art, and its object is to provide a vehicle air conditioning system in which the heat sink can be prevented from freezing in the dehumidifying heating mode and the target blow-out temperature can be achieved at the same time.

SOLUTION OF THE TASKS

A vehicle air conditioner of the present invention includes a compressor for compressing refrigerant, a heat sink for causing the refrigerant to dissipate heat and heat air supplied to a passenger compartment, a heat sink for causing the refrigerant to absorb heat and cool air supplied to the passenger compartment, one outside of the External heat exchanger provided in the passenger compartment, an external expansion valve for reducing the pressure of the refrigerant flowing into the external heat exchanger, an internal expansion valve for reducing the pressure of the refrigerant flowing into the heat sink and a control device, wherein at least one dehumidifying heating mode is executed by the control device, from which The refrigerant released from the compressor emits heat at the heat sink and the refrigerant that emitted heat is branched, with a part absorbing heat after a pressure reduction by means of the internal expansion valve on the heat sink t, while the other part after a pressure reduction by means of the external expansion valve am external heat exchanger absorbs heat, characterized in that the control device closes the internal expansion valve completely in the event that the temperature of the heat sink falls below a certain value.

A vehicle air conditioner according to an invention of claim 2 is characterized in that, in the above invention, the controller controls the number of revolutions of the compressor based on an index from which the temperature of the air blown into the passenger compartment can be detected.

A vehicle air conditioner according to an invention of claim 3 is characterized in that in one of the above inventions, the control device increases the valve opening degree of the external expansion valve in the course of a decrease in the temperature of the heat sink and in the event that the external expansion valve reaches a set maximum opening degree and the If the temperature of the heat sink falls below a certain value, the internal expansion valve closes completely.

A vehicle air conditioner according to an invention of claim 4 is characterized in that, in the above invention, the control device decreases the valve opening degree of the internal expansion valve in the event that the external expansion valve reaches a set maximum opening degree, and if the temperature of the heat sink falls below a certain value decreases, the internal expansion valve closes completely.

A vehicle air conditioning system according to an invention of claim 5 is characterized in that, in one of the above inventions, the control device after the internal expansion valve has been completely closed in the event that the temperature of the heat sink exceeds a certain value or a certain value lying above the certain value, the internal expansion valve opens to a certain valve opening degree.

A vehicle air conditioning system according to an invention of claim 6 is characterized in that in one of the above inventions, the control device executes a dehumidification cooling mode in which refrigerant discharged from the compressor gives off heat to an expansion valve and the external heat exchanger and the refrigerant that has given off heat by means of of the internal expansion valve experiences a pressure reduction, whereupon it absorbs heat at the heat sink, a control-related maximum value of the valve opening degree of the internal expansion valve in the dehumidifying heating mode being set smaller than a control-related maximum value of the valve opening degree of the internal expansion valve in the dehumidifying cooling mode.

EFFECTS OF THE INVENTION

According to the present invention, in a vehicle air conditioner that has a compressor for compressing refrigerant, a heat sink for causing the refrigerant to give off heat and heats air supplied to a passenger compartment, a heat sink for causing the refrigerant to absorb heat and cool air supplied to the passenger compartment an external heat exchanger provided outside the passenger compartment, an external expansion valve for reducing the pressure of the refrigerant flowing into the external heat exchanger, an internal expansion valve for reducing the pressure of the refrigerant flowing into the heat sink, and a control device, executed by the control device at least one dehumidifying heating mode, wherein refrigerant discharged from the compressor gives off heat at the heat sink and the refrigerant which has given off heat is branched, a part of which is after a pressure reduction by means of the internal expansion valve at the heat sink W poor, while the other part absorbs heat after a pressure reduction by means of the external expansion valve on the external heat exchanger, whereby the control device closes the internal expansion valve completely in the event that the temperature of the heat sink falls below a certain value, so that the refrigerant flows into the heat sink can be stopped without reducing the speed of the compressor, and thus the undesired freezing of the heat sink can be avoided.

The undesired decrease in the amount of air blown into the passenger compartment can also be eliminated in this way, and in particular in the event that, as in the invention of claim 2, the speed of the compressor is controlled on the basis of an index based on which the temperature of the air blown into the passenger compartment can be detected, the desired discharge temperature can be reached unhindered.

If in this case, as in the invention of claim 3, the control device increases the valve opening degree of the external expansion valve in the course of a decrease in the temperature of the heat sink and in the event that the external expansion valve reaches a set maximum degree of opening and the temperature of the heat sink below a certain value decreases, the internal expansion valve closes completely, it is possible to control the flow rate of refrigerant to the heat sink by controlling the external expansion valve and thereby reduce the To treat temperature of the heat sink at the external expansion valve, and in the event that reducing the flow rate of refrigerant to the heat sink by means of the external expansion valve reaches its limits, to stop the flow of refrigerant into the heat sink by means of the internal expansion valve.

In particular, when, as in the invention of claim 4, in the event that the external expansion valve reaches a set maximum opening degree, the control device decreases the valve opening degree of the internal expansion valve, and if the temperature of the heat sink falls below a specified value, the internal expansion valve fully closes, It is not necessary to completely close the internal expansion valve as long as the temperature of the heat sink does not fall below the specified value by reducing the valve opening degree of the internal expansion valve. This makes it possible to prevent the heat sink from freezing and at the same time to maintain the dehumidifying performance for the passenger compartment.

If the control device, as in the invention of claim 5, after the internal expansion valve has been completely closed in the event that the temperature of the heat sink exceeds a specified value or a specified value above the specified value, the internal expansion valve opens to a specified valve opening degree after the internal expansion valve has been fully closed due to an increase in the temperature of the heat sink, the supply of refrigerant to the heat sink can be resumed unhindered and dehumidification of the passenger compartment started.

If, as in the case of the invention of claim 6, the control device executes a dehumidification cooling mode in which refrigerant discharged from the compressor gives off heat to an expansion valve and the external heat exchanger and the refrigerant that has given off heat experiences a pressure reduction by means of the internal expansion valve, whereupon it absorbs heat at the heat sink, wherein a control-related maximum value of the valve opening degree of the internal expansion valve in the dehumidifying heating mode is set smaller than a control-related maximum value of the valve opening degree of the internal expansion valve in the dehumidifying cooling mode, a decrease in the temperature of the heat sink can be prevented in the dehumidifying heating mode, and at the same time in the dehumidifying mode gives a two-stage pressure-reducing effect by the external expansion valve and the internal expansion valve, by controlling the external expansion valve so that it opens a little wider is than in the dehumidification heating mode, an unhindered dehumidification cooling of the passenger compartment can be achieved.

Figure list

• 1 eine Konfigurationsansicht einer Fahrzeugklimaanlage einer Ausführungsform, auf die die vorliegende Erfindung angewandt wurde;
• 2 ein Blockschaubild eines elektrischen Schaltkreises einer Steuereinrichtung der Fahrzeugklimaanlage aus 1;
• 3 eine Konfigurationsansicht der Fahrzeugklimaanlage zur Erläuterung eines Heizmodus der Steuereinrichtung aus 2 mittels eines Wärmepumpen-Controllers;
• 4 eine Konfigurationsansicht der Fahrzeugklimaanlage zur Erläuterung eines Entfeuchtungsheizmodus eines Wärmepumpen-Controllers der Steuereinrichtung aus 2;
• 5 eine Konfigurationsansicht der Fahrzeugklimaanlage zur Erläuterung eines Entfeuchtungskühlmodus und eines Kühlmodus des Wärmepumpen-Controllers der Steuereinrichtung aus 2;
• 6 eine Konfigurationsansicht der Fahrzeugklimaanlage zur Erläuterung eines Modus zur Klimatisierung (Priorität) + Batteriekühlung und eines Modus zur Batteriekühlung (Priorität) + Klimatisierung der Steuereinrichtung aus 2 mittels des Wärmepumpen-Controllers;
• 7 eine Konfigurationsansicht der Fahrzeugklimaanlage zur Erläuterung eines Batteriekühlungsmodus (allein) der Steuereinrichtung aus 2 mittels des Wärmepumpen-Controllers;
• 8 ein Funktionsschaubild einer Kompressorsteuerung durch den Wärmepumpen-Controller der Steuereinrichtung aus 2;
• 9 ein erläuterndes Blockschaubild der Steuerung eines externen Expansionsventils durch den Wärmepumpen-Controller der Steuereinrichtung aus 2 im Entfeuchtungsheizmodus; und
• 10 ein erläuterndes Blockschaubild der Steuerung eines internen Expansionsventils durch den Wärmepumpen-Controller der Steuereinrichtung aus 2 im Entfeuchtungsheizmodus.

Show it:

• 1 Fig. 3 is a configuration view of a vehicle air conditioner of an embodiment to which the present invention is applied;
• 2 a block diagram of an electrical circuit of a control device of the vehicle air conditioning system 1 ;
• 3 a configuration view of the vehicle air conditioner for explaining a heating mode of the control device 2 by means of a heat pump controller;
• 4th a configuration view of the vehicle air conditioning system for explaining a dehumidification heating mode of a heat pump controller of the control device 2 ;
• 5 a configuration view of the vehicle air conditioner for explaining a dehumidification cooling mode and a cooling mode of the heat pump controller of the control device 2 ;
• 6th a configuration view of the vehicle air conditioning system to explain a mode for air conditioning (priority) + battery cooling and a mode for battery cooling (priority) + air conditioning of the control device 2 by means of the heat pump controller;
• 7th a configuration view of the vehicle air conditioning system for explaining a battery cooling mode (alone) of the control device 2 by means of the heat pump controller;
• 8th a functional diagram of a compressor control by the heat pump controller of the control device 2 ;
• 9 an explanatory block diagram of the control of an external expansion valve by the heat pump controller of the controller 2 in dehumidification heating mode; and
• 10 an explanatory block diagram of the control of an internal expansion valve by the heat pump controller of the controller 2 in dehumidification heating mode.

DESCRIPTION OF THE EMBODIMENTS

An embodiment of the present invention will now be described in detail based on the accompanying figures. 1 shows a configuration view of a Vehicle air conditioning 1 an embodiment of the present invention. The vehicle of the embodiment of the application of the present invention is an electric vehicle (EV) without an internal combustion engine (internal combustion engine) that is driven by supplying electric power to a motor (electric motor, not shown) used for driving, which is stored in a battery 55 installed in the vehicle is stored, and also a compressor described below 2 the vehicle air conditioning system according to the invention 1 is driven by the electric power from the battery 55.

That is, the vehicle air conditioning 1 of the exemplary embodiment leads in the electric vehicle, in which heating by means of waste engine heat is not possible, through the heat pump operation by means of the refrigerant circuit R. air conditioning of the passenger compartment and temperature regulation of the battery 55 by switching between the operating modes heating mode, dehumidifying heating mode, dehumidifying cooling mode, cooling mode, mode for air conditioning (priority) + battery cooling, mode for battery cooling (priority) + air conditioning and battery cooling mode (alone).

The vehicle is not limited to an electric vehicle, and the present invention is also useful for a so-called hybrid vehicle that uses both an internal combustion engine and a motor for driving. In the case of a vehicle on which the vehicle air conditioning system 1 of the embodiment is applied, the battery 55 can be charged by an external charger (quick charger or normal charger). The battery 55, a motor used for driving, inverter controlling them, and the like are each temperature regulation target objects installed in the vehicle, but the description will be given in the embodiment below using the battery 55 as an example.

The vehicle air conditioning 1 of the exemplary embodiment carries out the air conditioning (heating, cooling, dehumidification and ventilation), and an electrically driven compressor 2 for compressing refrigerant, a heat sink 4th that is in an air duct 3 an air conditioning unit 10 in which cabin air circulates is provided, into which via a refrigerant pipe 13G from the compressor 2 discharged hot high-pressure refrigerant flows and which causes the refrigerant to give off heat to the passenger compartment (heat is removed from the refrigerant), an external expansion valve 6th , which is formed by an electrically driven valve (electronic expansion valve), which causes a pressure reduction and expansion of the refrigerant during heating, an external heat exchanger 7th , which acts as a heat sink during cooling, which causes the refrigerant to give off heat, and during heating acts as an evaporator, which causes the refrigerant to absorb heat (the refrigerant absorbs heat) and performs a heat exchange between the refrigerant and the outside air, an internal expansion valve 8th , which is formed by an electrically driven expansion valve (electronic expansion valve) and causes a pressure reduction and expansion of the refrigerant, a heat sink serving as an evaporator 9 that are in the air duct 3 is provided and during cooling and dehumidifying causes the refrigerant to absorb (evaporate) heat from inside and outside the passenger compartment, an accumulator 12 and the like are connected one after the other by a refrigerant line 13 and in this way form a refrigerant circuit R. .

The external expansion valve 6th in addition to reducing the pressure and expanding the refrigerant that comes out of the heat sink 4th in the external heat exchanger 7th flows, also a complete closure. The internal expansion valve 8th in addition to reducing the pressure and expanding the refrigerant that enters the heat sink 9 flows, also a complete closure.

On the external heat exchanger 7th an external fan 15 is also provided. By the external fan 15 the external heat exchanger 7th Forcibly ventilated with outside air, it causes heat exchange between the outside air and the refrigerant, whereby there is a structure in which the external heat exchanger 7th is forced ventilation when the vehicle is stopped (i.e. at a driving speed of 0 km / h).

A refrigerant line 13A on the refrigerant outlet side of the external heat exchanger 7th is connected to a refrigerant line 13B to which an electromagnetic valve 17 (for cooling), which serves as an opening and closing valve, is opened to allow refrigerant to be sent to the heat sink 9 flows, is connected, and the refrigerant line 13B is sequentially through a check valve 18 and the internal expansion valve 8th with the refrigerant inlet side of the heat sink 9 tied together. The normal direction of the check valve 18 is the direction of the internal expansion valve 8th .

The one from the external heat exchanger 7th Exiting refrigerant line 13A branches into a refrigerant line 13D, and the branched refrigerant line 13D is via an electromagnetic valve 21 (for heating) as an opening and closing valve, which is opened during heating, with a refrigerant line 13C on the refrigerant outlet side of the heat sink 9 in connection. The refrigerant line 13C is connected to the inlet side of the accumulator 12 via a check valve 35, and the The outlet side of the accumulator 12 is connected to a refrigerant line 13K on the refrigerant suction side of the compressor 2 tied together. In the case of the check valve 35, the movement of the accumulator 12 is considered to be its regular direction, the refrigerant line 13D being connected to the refrigerant line 13C upstream of the refrigerant through the check valve 35.

With a refrigerant line 13E on the refrigerant outlet side of the heat sink 4th a strainer 19 is connected, and the refrigerant line 13E branches off before the external expansion valve 6th (refrigerant upstream) into a refrigerant line 13J and a refrigerant line 13F, and the one branched refrigerant line 13J is via the external expansion valve 6th with the refrigerant inlet side of the external heat exchanger 7th tied together. The other branched refrigerant line 13F is connected via an electromagnetic valve 22 (for dehumidification) formed as an opening and closing valve which is opened during dehumidification with the refrigerant downstream of the check valve 18 and refrigerant upstream of the internal expansion valve 8th arranged refrigerant line 13B in connection.

Thereby, the refrigerant line 13F is related to the series connection of the external expansion valve 6th , the external heat exchanger 7th and the check valve 18 are connected in parallel and form a bypass circuit for bypassing the external expansion valve 6th , the external heat exchanger 7th and the check valve 18.

In the air duct 3 upstream of the heat sink 9 Intake openings are formed as an outside air intake opening and an inside air intake opening (in 1 a suction opening 25 is shown representatively), wherein a suction switchover flap 26 is provided in the suction opening 25, which with respect to the in the air duct 3 introduced air switches between inside air from inside the passenger compartment (inside air circuit) and outside air from outside the passenger compartment (outside air introduction). An internal blower (fan) 27 is also provided downstream of the intake switchover flap 26, which is connected to the air duct 3 introduces indoor air or outdoor air.

Downstream (airflow) air blow from the heat sink 4th is in the air duct 3 an auxiliary heating device 23 is provided, which serves as an auxiliary heating device, which is formed in the exemplary embodiment by a PTC heating device (electrical heating device), and which allows the air to be heated that the passenger compartment via the heat sink 4th is fed. Air upstream of the heat sink 4th is in the air duct 3 an air mix flap 28 is provided, which adjusts the proportion with the air (inside air or outside air) in the air duct 3 that are in the air duct 3 and through the heat sink 9 has flowed through the heat sink 4th and the auxiliary heater 23 ventilates.

Also are air downstream of the heat sink 4th in the air duct 3 Exhaust openings FOOT (foot), VENT (ventilation) and DEF (def.) Formed (in 1 representatively shown as blow-out opening 29), and at the blow-out openings 29 a blow-out switchover flap 31 is provided, which carries out a switchover control of the blow-out of the air from the blow-out openings.

The vehicle air conditioning 1 also includes an apparatus temperature regulating device 61 that circulates the heat carrier to the battery 55 (temperature regulating target) and thus regulates the temperature of the battery 55. The device temperature regulating device 61 of the exemplary embodiment has a circulation pump 62 as a circulation device for circulating the heat carrier to the battery 55, a refrigerant-heat carrier heat exchanger 64 as a temperature regulating target object heat exchanger and a heat carrier heating device 63 as a heating device, and these and the battery 55 are connected in a ring-like manner by means of a heat carrier line 66.

In the case of the embodiment, the inlet of the heat carrier heater 63 is connected to the discharge side of the circulation pump 62, and the inlet of a heat carrier flow path 64A of the refrigerant-heat carrier heat exchanger 64 is connected to the outlet of the heat carrier heater 63. The outlet of the heat carrier flow path 64A of the refrigerant-heat carrier heat exchanger 64 is connected to the inlet of the battery 55, and the outlet of the battery 55 is connected to the suction side of the circulation pump 62.

As the heat carrier used for the apparatus temperature regulating device 61, for example, water, a refrigerant such as HFO-1234yf, a liquid such as a coolant or the like, or a gas such as air or the like can be used. In the exemplary embodiment, water is used as the heat carrier. The heat transfer heating device 63 is designed as an electrical heating device such as a PTC heating element. For example, a jacket structure is formed around the battery 55, in which the heat carrier can flow in a heat exchange relationship with the battery 55.

When the circulation pump 62 is operated, the heat carrier discharged from the circulation pump 62 flows to the heat carrier heater 63 and, if the Heat transfer device 63 generates heat, heats it there and then flows into the heat transfer medium flow path 64A of the refrigerant-heat transfer medium heat exchanger 64. The heat transfer medium exiting from the heat transfer medium flow path 64A of the refrigerant-heat transfer medium heat exchanger 64 flows to the battery 55, where the heat transfer medium exchanges heat with the battery 55 learns. After the heat transfer medium has been exchanged with the battery 55, it is circulated in the heat transfer medium line 66 by suction by the circulation pump 62.

Refrigerant downstream of the electromagnetic valve 22 of the refrigerant line 13F of the refrigerant circuit R. one end of a branch line 67 serving as a branch circuit is connected. In the exemplary embodiment, an auxiliary expansion valve 68 designed as an electrically driven valve (electronic valve) is provided on the branch line 67. The auxiliary expansion valve 68 causes a pressure reduction and expansion of the refrigerant flowing in a refrigerant flow path 64B of the refrigerant-heat carrier heat exchanger 64 described below, and can be completely closed.

The other end of the branch pipe 67 is connected to the refrigerant flow path 64B of the refrigerant-heat carrier heat exchanger 64, and one end of a refrigerant pipe 71 is connected to the outlet of the refrigerant flow path 64B, while the other end of the refrigerant pipe 71 is refrigerant downstream of the check valve 35 and refrigerant upstream of the accumulator 12 is connected to the refrigerant line 13C. The auxiliary expansion valve 68, the refrigerant line 64B of the refrigerant-heat carrier heat exchanger 64 and the like also form part of the refrigerant circuit R. and at the same time form part of the device temperature regulating device 61.

When the auxiliary expansion valve 68 is opened, refrigerant (part of the refrigerant or all of the refrigerant) flows out of the external heat exchanger 7th into the branch pipe 67, and after being reduced in pressure by the auxiliary expansion valve 68, it flows into the refrigerant flow path 64B of the refrigerant-heat carrier heat exchanger 64 and evaporates. While the refrigerant flows in the refrigerant flow path 64B, it absorbs heat from the heat carrier flowing in the heat carrier flow path 64A, and is then transferred from the refrigerant pipe 13K to the compressor via the refrigerant pipe 71, the refrigerant pipe 13C and the accumulator 12 2 sucked.

Next shows 2 a block diagram of the controller 11 the vehicle air conditioning 1 . The control device 11 is through an air conditioning controller 45 and a heat pump controller 32 each formed by a microcomputer, which is an example of a computer, and connected to a vehicle communication bus 65 that forms a CAN (Controller Area Network) or LIN (Local Interconnect Network). The compressor too 2 and the auxiliary heater 23, and the circulation pump 62 and the heat carrier heating heater 63 are connected to the vehicle communication bus 65, and the air conditioning controller 45 , the heat pump controller 32 , the compressor 2 , the auxiliary heater 23, the circulation pump 62 and the heat carrier heating heater 63 are configured to exchange data via the vehicle communication bus 65.

A vehicle controller 72 (ECU) for regulating general vehicle control including driving, a battery controller (BMS: Battery Management System) 73 for regulating control of charging and discharging of the battery 55, and a GPS navigation device 74 are connected to a vehicle communication bus 65 tied together. The vehicle controller 72, the battery controller 73, and the GPS navigation device 74 are constituted by a microcomputer, which is an example of a processor-equipped computer, and an air conditioning controller 45 and a heat pump controller 32 which the control device 11 are configured to exchange information (data) with the vehicle controller 72, the battery controller 73, and the GPS navigation device 74 via the vehicle communication bus 65.

With the climate controller 45 it is a higher-level controller that regulates the control of the passenger compartment air conditioning, and with the input of the air conditioning controller 45 are an outside air temperature sensor 33 that detects a vehicle outside air temperature Tam, an outside air humidity sensor 34 for detecting outside air humidity, an air conditioner suction temperature sensor 36 that detects a temperature of air flowing through the suction port 25 into the air duct 3 is sucked and into the heat sink 9 an inside temperature sensor 37 that detects a temperature of the air in the passenger compartment (inside air temperature Tin), an inside humidity sensor 38 that detects the humidity of the air in the passenger compartment, an internal CO2 concentration sensor 39 that detects a concentration of carbon dioxide in the passenger compartment , a blow-out temperature sensor 41 that detects a temperature of the air blown into the passenger compartment, a light incident sensor 51 of such a photo-sensor type that detects the amount of light incident into the passenger compartment, various outputs of vehicle speed sensors 52 that the Detect vehicle traveling speed (vehicle speed VSP), and connected to a climate control section 53 that performs air conditioning setting operations of the cabin such as switching of the setting temperature of the cabin, an operation mode and the like and information displays. Reference numeral 53A in the figures denotes a display provided as a display output device to the climate control section 53.

With the output of the climate controller 45 the external blower 15, the internal blower (fan) 27, the suction switching door 26, the air mix door 28, and the blow-out switching door 31 are connected and are controlled by the air conditioning controller 45 controlled.

With the heat pump controller 32 it is a controller that primarily controls the refrigerant circuit R. regulates, and with the input of the heat pump controller 32 are the outputs of a heat sink inlet temperature sensor 43 for detecting the refrigerant inlet temperature Tcxin of the heat sink 4th (which is also the refrigerant discharge temperature of the compressor 2 is), a heat sink outlet temperature sensor 44 for detecting the refrigerant outlet temperature Tci of the heat sink 4th , a suction temperature sensor 46 for detecting the refrigerant suction temperature Ts of the compressor 2 , a heat sink pressure sensor 47 for detecting the refrigerant pressure on the refrigerant outlet side of the heat sink 4th (Pressure of the heat sink 4th : Heat sink pressure Pci), a heat sink temperature sensor 48 for detecting the temperature of the heat sink 9 (Refrigerant temperature of the heat sink 9 : Heat sink temperature Te), a temperature sensor 49 of the external heat exchanger for detecting the refrigerant temperature at the outlet of the external heat exchanger 7th (Refrigerant evaporation temperature of the external heat exchanger 7th : External heat exchanger temperature TXO) and auxiliary heater temperature sensors 50A (driver's seat side) and 50B (passenger seat side) for detecting the temperature of auxiliary heater 23.

With the output of the heat pump controller 32 are the external expansion valve 6th , the electromagnetic valve 22 (for dehumidifying), the electromagnetic valve 17 (for cooling), the electromagnetic valve 21 (for heating), the internal expansion valve 8th and the auxiliary expansion valve 68 are connected and controlled by the heat pump controller 32 controlled. In the compressor 2 , in the auxiliary heater 23, in the circulation pump 62 and in the refrigerant heating heater 63 are each housed a controller, the controllers of the compressor 2 , the auxiliary heater 23, the circulation pump 62 and the refrigerant heating heater 63 via the vehicle communication bus 65 with the heat pump controller 32 replace and through the heat pump controller 32 being controlled.

The circulation pump 62 and the heat transfer medium heating heater 63 that constitute the appliance temperature regulating device 61 can also be controlled by the battery controller 73. With the battery controller 73, the outputs of a heat carrier temperature sensor 76 for detecting the temperature of the heat carrier on the inlet side of the heat carrier flow path 64A of the refrigerant-heat carrier heat exchanger 64 of the device temperature regulating device 61 (heat carrier temperature Tw) and a battery temperature sensor 77 for detecting the temperature of the battery 55 ( Temperature of the battery 55 itself: battery temperature Tcell) connected. Information on the remaining charge (stored amount of electricity) of the battery 55 and the charging of the battery 55 (information that charging is in progress, information that charging is completed, remaining charging time, etc.), the heat carrier temperature Tw, the battery temperature Tcell, the amount of heat generation of the battery 55 (calculated by the battery controller 73 from the supply amount and the like) and the like are transmitted from the battery controller 73 to the air conditioning controller via the vehicle communication bus 65 45 and the vehicle controller 72 is sent. Information about the completion of charging or the remaining charging time when charging the battery 55 is information supplied from the external charger such as the quick charger or the like. In addition, the vehicle controller 72 transmits the output Mpower of the motor used for driving to the heat pump controller 32 and the climate controller 45 sent.

The heat pump controller 32 and the climate controller 45 exchange data with each other via the vehicle communication bus 65 and control the various devices based on the outputs of the various sensors and the settings input to the climate control section 53, the configuration in this embodiment being such that the outputs of the outside air temperature sensor 33, the outside air humidity sensor 34, the Air conditioner suction temperature sensor 36, the inside air _{temperature sensor 37, the inside air humidity sensor 38, the CO 2} concentration sensor 39, the blowout temperature sensor 41, the incident light sensor 51, the vehicle speed sensor 52, the blown air amount Ga of the air entering the air duct 3 and through the air duct 3 flows (calculated by the climate controller 45 ), of the Air mix flap 28 caused blown air proportion SW (calculated by the air conditioning controller 45 ), the voltage (BLV) of the internal fan 27, the information from the aforementioned battery controller 73, the information from the GPS navigation device 74, and the climate control section 53 from the air conditioning controller 45 via the vehicle communication bus 65 to the heat pump controller 32 sent and for control by the heat pump controller 32 to be provided.

The heat pump controller 32 also sends data (information) to control the refrigerant circuit R. via the vehicle communication bus 65 to the climate controller 45 . The blown air portion SW caused by the air mix flap 28 is controlled by the air conditioning controller 45 calculated within a range of 0 ≤ SW ≤ 1. If SW = 1, then the air mix door 28 causes all of the through the heat sink 9 air leaked to the heat sink 4th and blown to the auxiliary heater 23.

The following is the description of the operation of the vehicle air conditioner 1 having the structure described above based on the following embodiment. In the exemplary embodiment, the vehicle air conditioning system switches 11 (Climate controller 45 , Heat pump controller 32 ) between the air conditioning modes of heating mode, dehumidification heating mode, dehumidification cooling mode, cooling mode and mode for air conditioning (priority) + battery cooling and the battery cooling modes for mode for battery cooling (priority) + air conditioning and battery cooling mode (alone).

The air conditioning modes of heating mode, dehumidification heating mode, dehumidification cooling mode and mode for air conditioning (priority) + battery cooling are carried out in the exemplary embodiment when the battery 55 is not charged, the ignition (IGN) is switched on and an air conditioning switch of the climate control section 53 is switched on. In remote-controlled operation (preconditioning, etc.), they are also carried out when the ignition is switched off. They are also carried out during the charging of the battery 55 if there is no battery cooling request and the air conditioning switch is switched on.

On the other hand, the battery cooling modes for battery cooling (priority) + air conditioning and battery cooling mode (alone) are executed when, for example, a plug is connected to a quick charger (external power source) and the battery 55 is being charged. However, the battery cooling mode (alone) is executed even when the battery 55 is not being charged, the air conditioning switch is turned off, and there is a battery cooling request (when driving when the outside air temperature is high, etc.).

When the ignition is on or the ignition is off but the battery 55 is charging, the heat pump controller operates 32 In this embodiment, the circulation pump 62 of the device temperature regulating device 61 and leaves, as with broken lines in the 3 until 7th shown, circulate heat transfer medium in the heat transfer line 66. The heat pump controller 32 of the embodiment also executes a battery heating mode in which the battery 55 is heated by causing the heat transfer medium heater 63 of the device temperature regulating device 61 to generate heat.

(1) heating mode

First, referring to FIG 3 the heating mode is described. The individual devices are controlled by the heat pump controller 32 and the climate controller 45 executed, but for the sake of simplicity, the description below is made with the heat pump controller 32 as a control subject. In 3 is the flow of the refrigerant in the refrigerant circuit R. shown in heating mode (solid arrows). If by the heat pump controller 32 (Automatic mode) or by manual air conditioning setting operation with the air conditioning control section 53 of the air conditioning controller 45 (manual mode) the heating mode is selected, the heat pump controller opens 32 the electromagnetic valve 21 and closes the electromagnetic valve 17 and the electromagnetic valve 22. Thus, there is a state in which the external expansion valve 6th is open, the internal expansion valve 8th and the auxiliary expansion valve 68 are fully closed, the compressor 2 and the fans 15, 27 are operated and the air mix flap 28 the proportion of the from the internal fan 27 to the heat sink 4th and adjusts air blown to the auxiliary heater 23.

This causes the compressor to flow 2 discharged hot gaseous high pressure refrigerant into the heat sink 4th . Because the air in the air duct 3 to the heat sink 4th is blown, the air experiences in the air duct 3 heat exchange with the high temperature refrigerant in the heat sink 4th and is heated. The refrigerant in the heat sink 4th however, it loses heat and is cooled, condensed and liquefied.

The refrigerant that is in the heat sink 4th has liquefied, comes out of the heat sink 4th and reaches the external expansion valve via the refrigerant lines 13E, 13J 6th . That in the external Expansion valve 6th Flowing refrigerant experiences a pressure reduction there and flows into the external heat exchanger 7th . That in the external heat exchanger 7th Flowing refrigerant evaporates and absorbs heat from outside air blown in by driving or by the external fan 15 (heat absorption). That means that the refrigerant circuit R. forms a heat pump. The cooled refrigerant flows out of the external heat exchanger 7th Via the refrigerant line 13A and the refrigerant line 13D and the electromagnetic valve 21 to the refrigerant line 13C and further through the refrigerant line 13C into the accumulator 12, where a gas-liquid separation takes place, whereupon the gaseous refrigerant from the refrigerant line 13K into the compressor 2 is sucked; this circulation repeats itself. The one on the heat sink 4th heated air is blown out through the exhaust port 29, whereby the passenger compartment is heated.

The heat pump controller 32 calculated from the heater target temperature TCO described below (target temperature of the heater temperature Thp described below), which is calculated from the exhaust target temperature TAO, which is the target temperature of the air blown into the passenger compartment (temperature target value of the air blown into the passenger compartment), the heat sink target pressure PCO and controls Based on the heat sink target pressure PCO and the heat sink pressure Pci (high pressure of the refrigerant circuit R. ) the speed NC of the compressor 2 , based on the heat sink refrigerant discharge temperature Tci detected by the heat sink outlet temperature sensor 44 4th and the heat sink pressure Pci detected by the heat sink pressure sensor 47, the degree of opening of the external expansion valve 6th and the degree of overcooling of the refrigerant at the outlet of the heat sink 4th .

The heat sink pressure Pci is an index by which the temperature of the air blown into the passenger compartment can be detected, but the blown temperature into the passenger compartment detected by the discharge temperature sensor 41 can also be used as an index.

If the through the heat sink 4th the heating output (heating output) is insufficient in relation to the required heating output, the heat pump controller is the same 32 this deficiency is eliminated by generating heat by means of the auxiliary heating device 23. In this way, the passenger compartment can be heated without any problems even when the outside air temperature or the like is low.

(2) Dehumidification heating mode

Next, referring to FIG 4th the dehumidification heating mode is described. In 4th is the flow of the refrigerant in the refrigerant circuit R. shown in dehumidification heating mode (solid arrows). The heat pump controller opens in the dehumidification heating mode 32 the electromagnetic valve 21 and the electromagnetic valve 22 and closes the electromagnetic valve 17. It also opens the external expansion valve 6th and the internal expansion valve 8th and the auxiliary expansion valve 68 closes completely. Then the compressor 2 and the fans 15, 27 are operated and the air mix door 28 adjusts the proportion of the from the internal fan 27 to the heat sink 4th and air blown to the auxiliary heater 23.

This causes the compressor to flow 2 discharged hot gaseous high pressure refrigerant into the heat sink 4th . Because the air in the air duct 3 to the heat sink 4th is blown, the air experiences in the air duct 3 heat exchange with the high temperature refrigerant in the heat sink 4th and is heated. The refrigerant in the heat sink 4th however, it loses heat and is cooled, condensed and liquefied.

The refrigerant that is in the heat sink 4th has liquefied, comes out of the heat sink 4th and a part of it flows into the refrigerant line 13J via the refrigerant line 13E and reaches the external expansion valve 6th . That into the external expansion valve 6th Flowing refrigerant experiences a pressure reduction there and flows into the external heat exchanger 7th . That in the external heat exchanger 7th Flowing refrigerant evaporates and absorbs heat from outside air blown in by driving or by the external fan 15 (heat absorption). The cooled refrigerant flows out of the external heat exchanger 7th Via the refrigerant line 13A and the refrigerant line 13D and the electromagnetic valve 21 to the refrigerant line 13C and through the refrigerant line 13C into the accumulator 12, where a gas-liquid separation takes place, whereupon the gaseous refrigerant from the refrigerant line 13K into the compressor 2 is sucked; this circulation repeats itself.

The rest of the condensed refrigerant that has passed through the heat sink 4th flows into the refrigerant line 13E is branched, and the branched refrigerant flows into the refrigerant line 13F and then arrives at the refrigerant line 13B via the electromagnetic valve 22. Then the refrigerant reaches the internal expansion valve 8th , learns in the internal expansion valve 8th a pressure reduction and then flows into the heat sink 9 and evaporates. The heat absorption effect of the Refrigerant in the heat sink 9 the proportion of water in the air blown from the internal fan 27 at the heat sink 9 condenses and adheres to it, thereby cooling and dehumidifying the air.

That in the heat sink 9 Evaporated refrigerant enters the refrigerant line 13C and is mixed with the refrigerant from the refrigerant line 13D (refrigerant from the external heat exchanger 7th ) united, whereupon it via the accumulator 12 from the refrigerant line 13K of the compressor 2 is sucked in and the cycle is repeated. The ones in the heat sink 9 dehumidified air is on its way through the heat sink 4th and the auxiliary heater 23 is reheated (in the case of heat generation thereof), thereby dehumidifying the passenger compartment.

The heat pump controller 32 controls in this exemplary embodiment on the basis of the heat sink set pressure PCO calculated from the heater set temperature TCO and the heat sink pressure Pci (high pressure of the refrigerant circuit) detected by the heat sink pressure sensor 47 R. ) the speed NC of the compressor 2 . It also controls the valve opening degree of the external expansion valve 6th and the internal expansion valve 8th based on the heat sink temperature Te, with the control of the external expansion valve 6th and the internal expansion valve 8th in the dehumidifying heating mode will be described in detail later.

If the through the heat sink 4th the heating output (heating output) is insufficient in relation to the required heating output, the heat pump controller is the same 32 this deficiency is eliminated in this dehumidification heating mode by generating heat by means of the auxiliary heating device 23. In this way, the passenger compartment can be heated with dehumidification without any problems even when the outside air temperature or the like is low.

(3) Dehumidification cooling mode

Next, referring to FIG 5 the dehumidification cooling mode is described. In 5 is the flow of the refrigerant in the refrigerant circuit R. shown in dehumidification cooling mode (solid arrows). The heat pump controller opens in dehumidification cooling mode 32 the electromagnetic valve 17 and closes the electromagnetic valve 21 and the electromagnetic valve 22. It also opens the external expansion valve 6th and the internal expansion valve 8th and the auxiliary expansion valve 68 closes completely. Then the compressor 2 and the fans 15, 27 are operated and the air mix door 28 adjusts the proportion of the from the internal fan 27 to the heat sink 4th and air blown to the auxiliary heater 23.

This causes the compressor to flow 2 discharged hot gaseous high pressure refrigerant into the heat sink 4th . Because the air in the air duct 3 to the heat sink 4th is blown, the air experiences in the air duct 3 heat exchange with the high temperature refrigerant in the heat sink 4th and is heated. The refrigerant in the heat sink 4th however, it loses heat and is cooled, condensed and liquefied.

That from the heat sink 4th Any refrigerant that has entered reaches the external expansion valve via the refrigerant lines 13E, 13J 6th and flows via the external expansion valve, which is controlled somewhat wider opening (having a larger opening area) in relation to the heating mode and the dehumidifying heating mode 6th in the external heat exchanger 7th . That in the external heat exchanger 7th Flowing refrigerant is cooled and condensed there with outside air blown in by driving or by the external fan 15. That from the external heat exchanger 7th The refrigerant that has leaked enters the refrigerant line 13B via the refrigerant line 13A and passes in sequence via the electromagnetic valve 17 and the check valve 18 to the internal expansion valve 8th . In the internal expansion valve 8th the refrigerant experiences a pressure reduction and then flows into the heat sink 9 and evaporates. Due to the heat absorption effect of the refrigerant, the water content in the air blown from the internal fan 27 condenses on the heat sink 9 and adheres to it, thereby cooling and dehumidifying the air.

That at the heat sink 9 Evaporated refrigerant reaches the accumulator 12 via the refrigerant line 13C and from there is transferred to the refrigerant line 13K by the compressor 2 sucked in; this circulation repeats itself. The ones in the heat sink 9 Cooled and dehumidified air is on its way through the heat sink 4th and the auxiliary heater 23 is re-heated (in the case of heat generation thereof) (the heating power being lower than that of the dehumidifying heating), thereby performing dehumidification cooling of the passenger compartment

The heat pump controller 32 controls the temperature of the heat sink based on the temperature of the heat sink sensed by the heat sink temperature sensor 48 9 (Heat sink temperature Te) and the heat sink target temperature TEO, which is the target temperature of the heat sink 9 (Target value of the heat sink temperature Te) is the speed NC of the compressor 2 so that the heat sink temperature Te reaches the heat sink target temperature TEO, and controls based on the heat sink pressure Pci (high pressure des Refrigerant circuit R. ) and the heat sink setpoint pressure PCO (setpoint of the heat sink pressure Pci) the degree of opening of the external expansion valve 6th such that the heat sink pressure Pci reaches the heat sink target pressure PCO, thus achieving the required amount of reheating (amount of reheating) by the heat sink 4th .

If the through the heat sink 4th the heating output (reheating output) is insufficient in relation to the required heating output, the heat pump controller is the same 32 this deficiency is also eliminated in this dehumidification cooling mode by generating heat by means of the auxiliary heating device 23. This enables dehumidifying cooling without lowering the temperature of the passenger compartment too far.

(4) cooling mode

Next, the cooling mode will be described. The flow of the refrigerant in the refrigerant circuit R. in cooling mode is the same as that 5 shown. This is how the heat pump controller opens 32 in the cooling mode, the electromagnetic valve 17 and closes the electromagnetic valve 21 and the electromagnetic valve 22. It also opens the external expansion valve 6th completely, the internal expansion valve opens 8th and the auxiliary expansion valve 68 closes completely. Then the compressor 2 and the fans 15, 27 are operated and the air mix door 28 adjusts the proportion of the from the internal fan 27 to the heat sink 4th and air blown to the auxiliary heater 23. The auxiliary heating device 23 is not made live.

This causes the compressor to flow 2 discharged hot gaseous high pressure refrigerant into the heat sink 4th . It is true that air blows in the air duct 3 to the heat sink 4th , but since its share is small (exclusively for reheating during cooling), it essentially only passes through it, and that from the heat sink 4th Any refrigerant that has passed reaches the refrigerant line 13J via the refrigerant line 13E. The refrigerant passes through the fully open external expansion valve 6th and continues to flow into the external heat exchanger 7th and is cooled, condensed and liquefied there with outside air blown in by driving or by the external fan 15.

That from the external heat exchanger 7th The refrigerant that has leaked enters the refrigerant line 13B via the refrigerant line 13A and passes in sequence via the electromagnetic valve 17 and the check valve 18 to the internal expansion valve 8th . In the internal expansion valve 8th the refrigerant experiences a pressure reduction and then flows into the heat sink 9 and evaporates. Due to the heat absorbing effect of the refrigerant, the air blown from the internal fan 27 becomes capable of exchanging heat with the heat sink 9 experiences, chilled.

That at the heat sink 9 Evaporated refrigerant reaches the accumulator 12 via the refrigerant line 13C and is from there via the refrigerant line 13K through the compressor 2 sucked in; this circulation repeats itself. The ones in the heat sink 9 cooled air is blown into the passenger compartment from the exhaust port 29, thereby cooling the passenger compartment. The heat pump controller controls in cooling mode 32 based on the temperature of the heat sink output from the heat sink temperature sensor 48 9 (Heat sink temperature Te) the speed NC of the compressor 2 .

(5) Air conditioning mode (priority) + battery cooling

Referring now to FIG 6th the mode for air conditioning (priority) + battery cooling is described. In 6th is the flow of the refrigerant in the refrigerant circuit R. shown in air conditioning (priority) + battery cooling mode (solid arrows). In the air conditioning (priority) + battery cooling mode, the heat pump controller opens 32 the electromagnetic valve 17 and closes the electromagnetic valve 21 and the electromagnetic valve 22. In addition, it fully opens the external expansion valve and opens the internal expansion valve 8th and the auxiliary expansion valve 68.

Then the compressor 2 and the fans 15, 27 are operated and the air mix door 28 adjusts the proportion of the from the internal fan 27 to the heat sink 4th and air blown to the auxiliary heater 23. In this operating mode, the auxiliary heating device 23 is not made live. The heat carrier heating device 63 is also not made live.

This causes the compressor to flow 2 discharged hot gaseous high pressure refrigerant into the heat sink 4th . It is true that air blows in the air duct 3 to the heat sink 4th , but since its share is small (exclusively for reheating during cooling), it essentially only passes through it, and that from the heat sink 4th Any refrigerant that has entered reaches the refrigerant line 13J via the refrigerant line 13E. As the external expansion valve 6th is fully open, the refrigerant flows into the external heat exchanger 7th and is cooled, condensed and liquefied there with outside air blown in by driving or by the external fan 15.

That from the external heat exchanger 7th Any refrigerant that has entered reaches the refrigerant line 13B via the refrigerant line 13A and branches after flowing through the electromagnetic valve 17 and the check valve 18, part of which through the refrigerant line 13B to the internal expansion valve 8th got. That in the internal expansion valve 8th Flowing refrigerant experiences a pressure reduction there and then flows into the heat sink 9 and evaporates. Due to the heat absorbing effect of the refrigerant, the air blown from the internal fan 27 becomes capable of exchanging heat with the heat sink 9 experiences, chilled.

That at the heat sink 9 The evaporated refrigerant reaches the accumulator 12 via the refrigerant line 13C and is from there via the refrigerant line 13K through the compressor 2 sucked in; this circulation repeats itself. The ones in the heat sink 9 cooled air is blown into the passenger compartment from the exhaust port 29, thereby cooling the passenger compartment.

The remaining refrigerant that has passed through the check valve 18 branches off, flows into a branch line 67 and reaches the auxiliary expansion valve 68. After the refrigerant has undergone a pressure reduction there, it flows into the refrigerant flow path 64B of the refrigerant-heat carrier heat exchanger 64 and evaporates there. A heat absorption effect is thereby achieved. The refrigerant evaporated in the refrigerant flow path 64B repeats the circulation in which it flows sequentially through the refrigerant pipe 71, the refrigerant pipe 13C and the accumulator 12, and out of the refrigerant pipe 13K through the compressor 2 sucked in (shown by the solid arrows in 6th ).

Since the circulation pump 62 is operated, the heat transfer medium emitted by the circulation pump 62 flows through the refrigerant heating device 64 and arrives through the heat transfer line 66 to the heat transfer medium flow path 64A of the refrigerant-heat transfer medium heat exchanger 64, where it undergoes a heat exchange with the refrigerant evaporated in the refrigerant flow path 64B, so that heat from it is absorbed and the heat transfer medium is cooled. The heat carrier that has emerged from the heat carrier flow path 64A of the refrigerant / heat carrier heat exchanger 64 reaches the battery 55, where it undergoes heat exchange with the battery 55. As a result, the battery 55 is cooled, and after the battery 55 has been cooled, the heat carrier is sucked in by the circulation pump 62; this circulation repeats itself (in 6th shown by the broken arrows).

In the air conditioning (priority) + battery cooling mode, the heat pump controller retains 32 the open state of the internal expansion valve 8th and controls based on the temperature of the heat sink output from the heat sink temperature sensor 48 9 (Heat sink temperature Te) the speed NC of the compressor 2 . In the exemplary embodiment, the auxiliary expansion valve 68 is controlled to open and close on the basis of the temperature of the heat carrier detected by the heat carrier temperature sensor 76 (heat carrier temperature Tw: sent by the battery controller 73). At this time, the heat carrier temperature Tw is used as an index for indicating the temperature of the battery 55 serving as the temperature regulating target in the embodiment (also hereinafter).

The heat pump controller 32 in this case uses, for example, the heat transfer medium temperature Tw as the setpoint and sets an upper limit value TUL and a lower limit value TLL with a fixed temperature difference above and below the heat transfer setpoint temperature TWO. If, from a state with the auxiliary expansion valve 68 closed, due to the generation of heat by the battery 55 or the like, the heat carrier temperature Tw rises to the upper limit value TUL (exceeds the upper limit value TUL or reaches the upper limit value TUL, hereinafter also), the auxiliary expansion valve 68 is opened . Thereby, refrigerant flows into the refrigerant flow path 64B of the refrigerant-heat carrier heat exchanger 64 and evaporates and cools the heat carrier flowing in the heat carrier flow path 64A, and therefore the battery 55 is cooled by the cooled heat carrier.

When the heat transfer medium temperature Tw subsequently falls to the lower limit value TLL (falls below the lower limit value TLL or reaches the lower limit value TLL, also in the following), the auxiliary expansion valve 68 is opened. Thereafter, this opening and closing of the auxiliary expansion valve 68 is repeated, and the cooling of the passenger compartment is prioritized, the heat carrier temperature Tw is controlled to the heat carrier target temperature TWO and the cooling of the battery 55 is carried out.

(6) Switching over the air conditioning mode

Dabei ist Tset die mittels des Klimaregelungsabschnitts 53 eingestellte Einstelltemperatur der Fahrgastzelle, Tin die durch den Innenlufttemperatursensor 37 erfasste Temperatur der Fahrgastzelleninnenluft, K der Koeffizient und Tbal ein Ausgleichswert, der aus der Einstelltemperatur Tset, der durch den Lichteinfallsensor 51 erfassten Lichteinfallmenge SUN und der durch den Außenlufttemperatursensor 33 erfassten Außenlufttemperatur Tam berechnet wird. Im Allgemeinen ist die Ausblassolltemperatur TAO umso höher, je niedriger die Außenlufttemperatur Tam ist, und sinkt mit ansteigender Außenlufttemperatur Tam.The heat pump controller 32 calculates the target outlet temperature TAO using the formula (1) below. The exhaust target temperature TAO is the target temperature of the air that is blown through the exhaust opening 29 into the passenger compartment. $$\text{TAO}=\left(\text{Tset}-\text{Tin}\right)\times \text{K}+\text{Tbal}\left(\text{f}\left(\text{Tset},\text{SUN},\text{Tam}\right)\right)$$

Tset is the setting temperature of the passenger compartment set by means of the climate control section 53, Tin is the temperature of the passenger compartment inside air detected by the inside air temperature sensor 37, K is the coefficient and Tbal is a compensation value that is derived from the setting temperature Tset, the amount of incident light SUN detected by the incident light sensor 51 and that of the Outside air temperature sensor 33 detected outside air temperature Tam is calculated. In general, the lower the outside air temperature Tam, the higher the target blow-out temperature TAO, and it decreases as the outside air temperature Tam increases.

When starting the heat pump controller 32 One of the air conditioning modes is selected based on the outside air temperature Tam detected by the outside air temperature sensor 33 and the target blowout temperature TAO. If changes in the operating conditions, the ambient conditions or the setting conditions occur after the start, such as the outside air temperature Tam, the target blow-out temperature TAO, the heat transfer medium temperature Tw, or the battery temperature Tcell, the corresponding air conditioning mode is selected in accordance with a battery cooling request from the battery controller 73 (mode transition request) and switched to it.

(7) Battery cooling mode (priority) + air conditioning

Next, the operation when charging the battery 55 will be described. For example, when a plug for charging from a quick charger (external power source) is connected and the battery 55 is charging (this information is sent by the battery controller 73) and there is a battery cooling request regardless of the ignition on / off control (IGN) and the air conditioning switch of the air conditioning section 53 is turned on, the heat pump controller performs 32 the mode for battery cooling (priority) + air conditioning. The flow of the refrigerant in the refrigerant circuit R. is the same in this mode for battery cooling (priority) + air conditioning as in the mode for air conditioning (priority) + battery cooling off 6th .

However, the heat pump controller retains 32 In this exemplary embodiment, in the mode for battery cooling (priority) + air conditioning, the open state of the auxiliary expansion valve 68 contributes and controls the rotational speed NC of the compressor on the basis of the heat carrier temperature Tw detected by the heat carrier temperature sensor 76 (sent by the battery controller 73) 2 . In addition, in the embodiment, based on the temperature of the heat sink detected by the heat sink temperature sensor 48 9 (Heat sink temperature Te) the internal expansion valve 8th opening and closing controlled.

The heat pump controller 32 in this case uses, for example, the heat sink temperature Te as the setpoint value and sets an upper limit value TeUL and a lower limit value TeLL with a fixed temperature difference above and below the heat sink setpoint temperature TEO. When from a condition with the internal expansion valve fully closed 8th the heat sink temperature Te rises to the upper limit value TeUL (exceeds the upper limit value TeUL or reaches the upper limit value TeUL, hereinafter also), the internal expansion valve 8th opened. This causes the refrigerant to flow into the heat sink 9 and evaporates and cools the in the air duct 3 flowing air.

If the heat sink temperature Te subsequently falls to the lower limit value TeLL (falls below the lower limit value TeLL or reaches TeLL, also in the following), the internal expansion valve is activated 8th completely closed. After that, this opens and closes the internal expansion valve 8th repeatedly, and prioritizing the cooling of the battery 55, the heat sink temperature Te is controlled to the heat sink target temperature TEO and the cooling of the passenger compartment is performed.

(8) Battery cooling mode (alone)

If, regardless of the on / off control of the ignition, with the air conditioning switch of the air conditioning section 53 turned off, a plug for charging from a quick charger (external power source) is connected and the battery 55 is charged and there is a battery cooling request, the heat pump controller performs 32 the battery cooling mode (alone). However, it is executed even when the battery 55 is not being charged, the air conditioning switch is turned off, and there is a battery cooling request (when driving when the outside air temperature is high, etc.). In 7th is the flow of the refrigerant in the refrigerant circuit R. shown in battery cooling mode (alone) (solid arrows). In battery cooling mode (alone) the heat pump controller opens 32 the electromagnetic valve 17 and closes the electromagnetic valve 21 and the electromagnetic valve 22. Also, it opens the auxiliary expansion valve 68 and closes the internal expansion valve 8th Completely.

The compressor 2 and the external fan 15 are operated. The internal fan 27 is not operated, and the auxiliary heater 23 is also not made live. In this In the operating mode, the heat carrier heating device 63 is also not made live.

This causes the compressor to flow 2 discharged hot gaseous high pressure refrigerant into the heat sink 4th . The air in the air duct 3 will not get into the heat sink 4th blown, but just happens, and that from the heat sink 4th Any refrigerant that has passed reaches the refrigerant line 13J via the refrigerant line 13E. As the external expansion valve 6th is fully open, the refrigerant flows into the external heat exchanger 7th and there is cooled, condensed and liquefied with outside air blown in by the external fan 15.

That from the external heat exchanger 7th The refrigerant that has entered reaches the refrigerant line 13B via the refrigerant line 13A, flows through the electromagnetic valve 17 and the check valve 18 in sequence, then flows completely into the branch line 67 and reaches the auxiliary expansion valve 68. After the refrigerant has undergone a pressure reduction there, it flows into the refrigerant flow path 64B of the refrigerant-heat carrier heat exchanger 64 and evaporates there. A heat absorption effect is thereby achieved. The refrigerant evaporated in the refrigerant flow path 64B repeats the circulation in which it flows sequentially through the refrigerant pipe 71, the refrigerant pipe 13C and the accumulator 12, and out of the refrigerant pipe 13K through the compressor 2 sucked in (shown by the solid arrows in 7th ).

Since the circulation pump 62 is operated, the heat carrier released by the circulation pump 62 in turn flows through the refrigerant heating device 63 and passes through the heat carrier line 66 to the heat carrier flow path 64A of the refrigerant-heat carrier heat exchanger 64, where the refrigerant evaporated in the refrigerant flow path 64B absorbs heat therefrom and the heat carrier is cooled will. The heat carrier that has emerged from the heat carrier flow path 64A of the refrigerant / heat carrier heat exchanger 64 reaches the battery 55, where it undergoes heat exchange with the battery 55. As a result, the battery 55 is cooled, and after the battery 55 has been cooled, the heat carrier is sucked in by the circulation pump 62; this circulation repeats itself (in 7th shown by the broken arrows).

The heat pump controller also controls in battery cooling mode (alone) 32 based on the heat carrier temperature Tw detected by the heat carrier temperature sensor 76, the rotational speed NC of the compressor 2 and thereby cools the battery 55.

(9) Battery warming mode

While the air conditioning operation is being carried out or the battery 55 is being charged, the heat pump controller is performing 32 turn off the battery warming mode. The heat pump controller operates in battery warming mode 32 the circulation pump 62 and makes the heat carrier heating heater 63 current-carrying. It also closes the auxiliary expansion valve 68 completely.

The heat carrier released by the circulation pump 62 therefore passes through the heat carrier line 66 to the heat carrier heating device 63. Since the heat carrier heating device 63 now generates heat, the heat carrier is heated by the heat carrier heating device 63 and its temperature rises, whereupon it goes to the heat carrier flow path 64A of the refrigerant heat carrier Heat exchanger 64 and from there to the battery 55 and undergoes a heat exchange with the battery 55. As a result, the battery 55 is heated, and after the battery 55 has been heated, the heat carrier is sucked in by the circulation pump 62; this circulation repeats itself.

By using the heat pump controller 32 controls the power supply of the heat carrier heater 63 in the battery heating mode based on the heat carrier temperature Tw detected by the heat carrier temperature sensor 76, it regulates the heat carrier temperature Tw to the specified heat carrier target temperature TWO and heats the battery 55.

(10) Control of the compressor 2 in heating mode and in dehumidifying heating mode

The heat pump controller 32 calculated in the heating mode and in the dehumidifying heating mode based on the heat sink pressure Pci according to the functional diagram 8th the target speed of the compressor 2 (Set compressor speed) TGNCh. 8th is a functional diagram of the heat pump controller 32 which sets the target speed of the compressor based on the heat sink pressure Pci 2 (Compressor target speed) TGNCh calculated. A VK (feedforward) operation amount calculating section 78 of the heat pump controller 32 calculated based on the outside air temperature Tam obtained from the outside air temperature sensor 33, a blower voltage BLV of the internal blower 27, a blown air amount ratio SW of the air mix door 28 obtained by SW = (TAO - Te) / (Thp - Te), a target supercooling temperature TGSC, the the setpoint of an overcooling degree SC of the refrigerant at the outlet of the heat sink 4th is the Target heater temperature TCO, which is the target value of the heater temperature Thp, and a target heat sink pressure PCO, which is the target value of the pressure of the heat sink 4th is a VK operation amount TGNChff of the target compressor speed.

The heater temperature Thp is an air temperature blown air downstream of the heat sink 4th (Estimated value) derived from the heat sink pressure Pci detected by the heat sink pressure sensor 47 and the heat sink refrigerant outlet temperature Tci detected by the heat sink outlet temperature sensor 44 4th is calculated (estimated). The supercooling temperature SC is determined by the refrigerant inlet temperature Tcxin and the refrigerant outlet temperature Tci of the heat sink detected by the heat sink inlet temperature sensor 43 and the heat sink outlet temperature sensor 44 4th calculated.

The heat sink target pressure PCO is calculated based on the target supercooling temperature TGSC and the heater target temperature TCO by a target value calculation section 79. An RK (feedback) operation amount calculation section 81 calculates an RK operation amount TGNChfb of the compressor target speed based on the heat sink target pressure PCO and the heat sink pressure Pci by PID calculation and PI calculation, respectively. The VK operation amount TGNChff calculated by the VK operation amount calculating section 78 and the RK operation amount TGNChfb calculated by the RK operation amount calculating section 81 are added in an adder 82 and fed to a threshold setting section 83 as TGNCh00.

A control-related lower speed limit ECNpdLimLo and upper speed limit ECNpdLimHi are set at the limit value setting section 83, and it is determined as TGNCh0, whereupon it is determined as the compressor target speed TGNCh via a compressor switch-off control section 84. The heat pump controller controls in normal mode 32 by means of this compressor target speed TGNCh calculated on the basis of the heat sink pressure Pci, the operation (speed NC) of the compressor 2 .

When the compressor target speed TGNCh reaches the lower speed limit ECNpdLimLo and a state in which the heat sink pressure Pci rises to the upper limit value PUL (exceeds the upper limit value PUL or the upper limit value PUL) with a certain upper limit value PUL and lower limit value PLL set above and below the heat sink target pressure PCO Limit value PUL reached, hereinafter also), continues for a certain time th1, the compressor cut-off control section 84 stops the compressor 2 and enters an on / off mode for on / off control of the compressor 2 a.

When in this on / off mode the compressor 2 the heat sink pressure Pci falls to the lower limit value PLL (falls below the lower limit value PLL or reaches the lower limit value PLL, also in the following), the compressor 2 started and operated with the lower speed limit ECNpdLimLo for the compressor target speed TGNCh, and if the heat sink pressure Pci rises in this state to the upper limit value PUL, the compressor 2 stopped again. The compressor is therefore operated (switched on) and stopped (switched off) 2 at the lower speed limit ECNpdLimLo. If after the heat sink pressure Pci has dropped to the lower threshold PUL and the compressor starts 2 a state in which the heat sink pressure Pci does not rise above the lower threshold value PUL continues for a certain time th2 becomes the on / off mode of the compressor 2 ends and a return to normal mode occurs.

(11) Control of the external expansion valve 6th and the internal expansion valve 8th in dehumidification heating mode

Next, referring to FIG 9 and 10 an actual example of the control of the external expansion valve 6th and the internal expansion valve 8th in dehumidification heating mode by the heat pump controller 32 described. The heat pump controller 32 controls in the dehumidification heating mode as discussed based on the heat sink target pressure PCO calculated from the heater target temperature TCO and the heat sink pressure Pci (high pressure of the refrigerant circuit) detected by the heat sink pressure sensor 47 R. ) the speed NC of the compressor 2 ( 8th ), and controls the valve opening degree of the external expansion valve 6th based on the heat sink temperature Te and the valve opening degree of the internal expansion valve 8th based on the valve opening degree of the external expansion valve 6th and the heat sink temperature Te.

(11-1) Control of the external expansion valve 6th in dehumidification heating mode

First, referring to FIG 9 an embodiment of the control of the external expansion valve 6th in dehumidification heating mode by the heat pump controller 32 described. 9 shows the course of the valve opening degree of the external expansion valve 6th in dehumidification heating mode. In the exemplary embodiment, the heat pump controller changes 32 based on the heat sink temperature Te detected by the heat sink temperature sensor 48, the valve opening degree des external expansion valve 6th in three stages. When in the fully closed state of the external expansion valve 6th the heat sink temperature Te drops below a heat sink target temperature TEO-A, the external expansion valve becomes 6th opened and its valve opening degree to a certain valve opening degree 1 set. A is a certain positive value. Also is the valve opening degree 1 a certain degree of opening that is smaller than a set maximum degree of opening described below.

When the valve opening degree of the external expansion valve 6th on the valve opening degree 1 is set and the heat sink temperature Te further decreases below a heat sink target temperature TEO-B, the set maximum opening degree of the external expansion valve becomes the valve opening degree 6th set. This set maximum degree of opening is a control-related maximum value of the external expansion valve set for the dehumidification heating mode 6th . The relationship A <B applies to B. The heat pump controller 32 thus increases the valve opening degree of the external expansion valve 6th as the heat sink temperature Te drops below the heat sink target temperature TEO.

Because along with increasing the valve opening degree of the external expansion valve 6th to the internal expansion valve 8th The amount of diverted refrigerant decreases, so does the amount of refrigerant in the heat sink 9 flowing refrigerant reduced. When the valve opening degree of the external expansion valve 6th is the set maximum degree of opening and the heat sink temperature Te rises and becomes higher than the heat sink setpoint temperature TEO + C, the heat pump controller decreases 32 the valve opening degree of the external expansion valve 6th on the valve opening degree 1 . C is also a certain positive value.

When the valve opening degree of the external expansion valve 6th the valve opening degree 1 and the heat sink temperature Te continues to rise above the heat sink temperature TEO + D, the external expansion valve becomes 6th completely closed. The relationship C <D applies to D. The heat pump controller 32 thus reduces the valve opening degree of the external expansion valve 6th in the course of the increase in the heat sink temperature Te above the heat sink setpoint temperature TEO, which is why the to the internal expansion valve 8th The amount of refrigerant diverted increases and so does the amount of refrigerant entering the heat sink 9 flowing refrigerant increases.

By thus the heat pump controller 32 in dehumidification heating mode basically the valve opening degree of the external expansion valve 6th adjusts, it controls the heat sink temperature Te in the range of the heat sink target temperature TEO. This is called normal control of the external expansion valve 6th designated.

(11-2) Control of the internal expansion valve 8th in dehumidification heating mode

Referring now to FIG 10 an embodiment of the control of the internal expansion valve 8th in dehumidification heating mode by the heat pump controller 32 described. 10 shows the course of the valve opening degree of the internal expansion valve 8th in dehumidification heating mode. When the valve opening degree of the external expansion valve 6th is not the set maximum opening degree, the heat pump controller performs 32 the normal control state, and when the valve opening degree of the external expansion valve 6th becomes the set maximum opening degree, it goes to the opening and closing control state.

So sets the heat pump controller 32 the valve opening degree of the internal expansion valve in the normal control state 8th to a certain degree of valve opening 2 fixed. This valve opening degree 2 is a control-related maximum value of the internal expansion valve 8th in dehumidification heating mode (the set maximum degree of opening of the internal expansion valve 8th in dehumidification heating mode). The control-related maximum value of the internal expansion valve 8th in dehumidification heating mode is smaller than the control-related maximum value of the internal expansion valve 8th set in dehumidification cooling mode. The reason is that in the dehumidification cooling mode, the two-stage pressure reducing effect of the external expansion valve 6th and the internal expansion valve 8th is present. By setting the control-related maximum value of the internal expansion valve 8th As in the exemplary embodiment, the temperature of the heat sink will drop in the dehumidification heating mode 9 prevented, and in dehumidification cooling mode there is a control that the external expansion valve 6th opens slightly wider than in the dehumidifying heating mode, so that unhindered dehumidifying cooling of the passenger compartment can be achieved.

When, in this normal control state, the valve opening degree of the external expansion valve 6th the set maximum opening degree, the heat pump controller goes 32 into the opening and closing control state. When transitioning to the open and close control state, the heat pump controller downsizes 32 first the valve opening degree of the internal expansion valve 8th to a certain degree of valve opening 3 . This valve opening degree 3 is a certain degree of opening, which is smaller than the valve opening degree 2 is. So if the heat pump controller 32 with the valve opening degree of the external expansion valve 6th cannot further control the heat sink temperature Te (since the valve opening degree of the external expansion valve 6th cannot be increased any further), it goes into the open and close control state and decreases the valve opening degree of the internal expansion valve 8th on the valve opening degree 3 . In this open and close control state, the heat pump controller fixes 32 the external expansion valve 6th to the set maximum opening degree.

In the open and close control status, the heat pump controller leads 32 switching control of the internal expansion valve based on the change in the heat sink temperature Te detected by the heat sink temperature sensor 48 8th between the valve opening degree 3 and complete closure. When the external expansion valve 6th reaches the set maximum opening degree and despite reducing the valve opening degree of the internal expansion valve 8th on the valve opening degree 3 the heat sink temperature Te falls further than a certain value t1, the heat pump controller closes 32 so the internal expansion valve 8th Completely. This means that refrigerant no longer flows into the heat sink 9 , The heat sink temperature Te is suppressed from lowering and the heat sink is prevented from freezing 9 prevented. The specific value t1 is a specific low value at or above the freezing point (zero point).

When the internal expansion valve 8th is completely closed and the temperature of the air blown into the passenger compartment (blow-out temperature) changes, the heat pump controller reacts 32 as described, to this change in the discharge temperature by means of a speed control of the compressor 2 based on the heat sink target pressure PCO and the heat sink pressure Pci and controls the discharge temperature to a target value.

If after fully closing the internal expansion valve 8th the heat sink temperature Te rises above a further specific value t2, which is higher than the specific value t1, the heat pump controller opens 32 the internal expansion valve 8th and sets its valve opening degree to the valve opening degree 3 (certain valve opening degree). Notwithstanding the above, in the event that the heat sink temperature Te exceeds the specified value t1, the internal expansion valve can also 8th be opened. This causes refrigerant to flow into the heat sink 9 and dehumidification of the passenger compartment is resumed.

Then, when the heat sink temperature Te drops below the certain value t1, the heat pump controller closes 32 the internal expansion valve again 8th Completely. In this open and close control state, the heat pump controller reverses 32 return to the normal control state when a certain return condition is met. This return condition is, for example, that the heat sink temperature Te has risen to a temperature above the certain value t2, or that a certain time has passed in addition to it, or the like.

Because the heat pump controller 32 who is the control device 11 As described above, forms the internal expansion valve in the event that the heat sink temperature Te falls below the specified value t1 8th closes completely, the flow of the refrigerant into the heat sink can 9 can be stopped without changing the NC speed of the compressor 2 to reduce, and so the unwanted freezing of the heat sink 9 be avoided.

The undesired decrease in the amount of air blown into the passenger compartment can also be eliminated in this way, and in particular in the event that, as in the exemplary embodiment, the speed NC of the compressor 2 is controlled based on the heat sink pressure Pci (index by which the temperature of the air blown into the passenger compartment can be detected), the target blow-out temperature can be achieved unhindered.

Because the heat pump controller 32 in the embodiment, in this case, as the heat sink temperature Te drops, the valve opening degree of the external expansion valve 6th enlarged and in the event that the external expansion valve 6th reaches the set maximum degree of opening and the heat sink temperature Te below the specific value t1 decreases, the internal expansion valve 8th closes completely, it is possible by controlling the external expansion valve 6th the amount of refrigerant flowing to the heat sink 9 to control and thereby the drop in the heat sink temperature Te at the external expansion valve 6th to deal with, and in the event that reducing the flow rate of refrigerant to the heat sink 9 by means of the external expansion valve 6th reaches its limits, the flow of refrigerant into the heat sink 9 by means of the internal expansion valve 8th to stop.

Especially since the heat pump controller 32 in the exemplary embodiment for the case that the external expansion valve 6th reaches the set maximum opening degree, the valve opening degree of the internal expansion valve 8th the valve opening degree 2 on the valve opening degree 3 and, if the heat sink temperature Te falls below the certain value t1, the internal expansion valve 8th fully closes does not mean that the internal expansion valve is fully closed 8th required as long as by decreasing the valve opening degree of the internal expansion valve 8th the heat sink temperature Te does not decrease below the certain value t1. This makes it possible to freeze the heat sink 9 to prevent and at the same time to maintain the dehumidification performance for the passenger compartment.

Because the heat pump controller 32 in the exemplary embodiment also after the internal expansion valve has been completely closed 8th in the event that the heat sink temperature Te exceeds the certain value t1 or the certain value t2 lying above this, the internal expansion valve 8th on the specific valve opening degree 3 opens after the internal expansion valve has been fully closed 8th by an increase in the heat sink temperature Te, the supply of refrigerant to the heat sink 9 can be resumed unhindered and dehumidification of the passenger compartment started.

There is no restriction on the structure of the refrigerant circuit R. , Numerical values and conditions for the transition (change) of the control of the external expansion valve 6th or the internal expansion valve 8th before, and it is obvious that these can be changed as long as the essence of the invention is not deviated from. The present invention in the exemplary embodiment was also based on the vehicle air conditioning system 1 which has the operating modes of heating mode, dehumidifying heating mode, dehumidifying cooling mode, cooling mode, air conditioning mode (priority) + battery cooling, etc., but is not limited thereto, and the present invention is also applicable to a vehicle air conditioner that has, for example, the dehumidifying heating mode and the dehumidifying cooling mode can perform.

List of reference symbols

1

Vehicle air conditioning

2

compressor

3

Air flow duct

4th

Heat sink

6th

external expansion valve

7th

external heat exchanger

8th

internal expansion valve

9

Heat sink

11

Control device

32

Heat pump controller

45

Climate controller

R.

Refrigerant circulation

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 201494673 [0004]

Claims (6)

A vehicle air conditioning system comprising: a compressor for compressing refrigerant, a heat sink for causing the refrigerant to give off heat and heat air supplied to a passenger compartment, a heat sink for causing the refrigerant to absorb heat and to cool air supplied to the passenger compartment, one provided outside the passenger compartment external heat exchanger, an external expansion valve for reducing the pressure of the refrigerant flowing into the external heat exchanger, an internal expansion valve for reducing the pressure of the refrigerant flowing into the heat sink and a control device, the control device executing at least one dehumidifying heating mode, with discharged from the compressor Refrigerant releases heat at the heat sink and the refrigerant that has released heat is branched, with one part absorbing heat after a pressure reduction by means of the internal expansion valve on the heat sink, while the other part absorbs heat il absorbs heat after a pressure reduction by means of the external expansion valve on the external heat exchanger, characterized in that the control device completely closes the internal expansion valve in the event that the temperature of the heat sink falls below a certain value. Vehicle air conditioning after Claim 1 , characterized in that the control device controls the speed of the compressor on the basis of an index by means of which the temperature of the air blown into the passenger compartment can be detected. Vehicle air conditioning after Claim 1 or 2 , characterized in that the control device increases the valve opening degree of the external expansion valve in the course of a decrease in the temperature of the heat sink and, in the event that the external expansion valve reaches a set maximum degree of opening and the temperature of the heat sink falls below a certain value, the internal expansion valve completely closes. Vehicle air conditioning after Claim 3 , characterized in that the control device, in the event that the external expansion valve reaches a set maximum opening degree, reduces the valve opening degree of the internal expansion valve, and if the temperature of the heat sink falls below a certain value, the internal expansion valve closes completely. Vehicle air conditioning according to one of the Claims 1 until 4th , characterized in that after the internal expansion valve has been completely closed, the control device opens the internal expansion valve to a certain degree of valve opening in the event that the temperature of the heat sink exceeds a certain value or a certain value lying above the certain value. Vehicle air conditioning according to one of the Claims 1 until 5 , characterized in that the control device executes a dehumidification cooling mode in which refrigerant discharged from the compressor releases heat to an expansion valve and the external heat exchanger and the refrigerant that has released heat experiences a pressure reduction by means of the internal expansion valve, whereupon it heats the heat sink absorbed, wherein a control-related maximum value of the valve opening degree of the internal expansion valve in the dehumidifying heating mode is set smaller than a control-related maximum value of the valve opening degree of the internal expansion valve in the dehumidifying cooling mode.

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