System for air conditioning the air of a passenger compartment of a motor vehicle and method for operating the system

Abstract

A system for air conditioning air of a passenger compartment of a motor vehicle, the system having a refrigerant circuit having: a compressor; a first refrigerant / air heat exchanger operable as a condenser / gas cooler for heating incoming air of the passenger compartment; a refrigerant path having a second refrigerant / air heat exchanger and a third refrigerant / air heat exchanger, the second refrigerant / air heat exchanger being operable as a condenser / gas cooler or evaporator for heat exchange with ambient air and having an upstream first expansion member, a third refrigerant / air heat exchanger operable as an evaporator for conditioning intake air of the passenger compartment and having an upstream second expansion member; and a refrigerant path having a refrigerant / coolant heat exchanger operable as an evaporator for heat exchange between a coolant for controlling the temperature of at least one component of the driveline of the motor vehicle and the refrigerant and having an upstream third expansion member.

Description

Technical Field

[0001] The invention relates to a system for air conditioning the air of a passenger compartment of a motor vehicle. The system has a refrigerant circuit having: a compressor; a first refrigerant / air heat exchanger, which can be operated as a condenser / gas cooler for heating the intake air of the passenger compartment; a refrigerant path having a second refrigerant / air heat exchanger and a third refrigerant / air heat exchanger, which can be operated as a condenser / gas cooler or an evaporator for heat exchange with ambient air, and a refrigerant path having a refrigerant / coolant heat exchanger, which can be operated as an evaporator for heat exchange between a coolant and a refrigerant for controlling the temperature of at least one component of a powertrain of a motor vehicle. The invention also relates to a method for operating the system.

[0002] Motor vehicles with different drive concepts are known from the prior art. These concepts are based on a drive by means of a combustion engine, an electric motor or a combination of both motor types. Thus, a motor vehicle with a combination of an internal combustion engine drive and an electric motor drive has a hybrid drive, so that the motor vehicle can be driven electrically, electrically / internal combustion engine or by internal combustion engine as required. Background Art

[0003] As is known, electric vehicles and vehicles with hybrid drive as well as fuel cell vehicles and vehicles driven with internal combustion engines having high energy efficiency do not generate sufficient waste heat to heat the passenger compartment corresponding to the requirements for thermal comfort at low ambient temperatures.

[0004] A first cost-effective and installation space-saving solution for heating the intake air for the passenger compartment is an electric heater, which is formed, for example, as a PTC heater for heating the intake air flowing into the passenger compartment, connected to a refrigerant circuit for cooling and dehumidifying the intake air exclusively. However, systems provided with a PTC heater have high energy consumption at low outlet temperatures for heating the intake air for the passenger compartment. An electric auxiliary heater which cannot be operated in an energy-saving manner reduces the range of a battery-electrically driven motor vehicle.

[0005] A second, more energy-efficient solution for heating the intake air for the passenger compartment is an air conditioning system with heat pump functionality, which uses a different heat source and heat sink, but which requires significantly more installation space than the first solution with an electric heater.

[0006] When operating an air conditioning system of a motor vehicle with a heat pump function in cooling mode, in particular when operating a refrigerant circuit of the air conditioning system with an evaporator and a condenser / gas cooler of the refrigerant, the heat required for the evaporation of the refrigerant is absorbed in the evaporator from the intake air of the passenger compartment or from the coolant circuit at a lower temperature level and pressure level. The coolant circuit can be used, for example, to control the temperature, in particular for cooling electrical components of an electrically driven motor vehicle, such as a traction battery. In the condenser / gas cooler, the heat absorbed by the coolant can be transferred to the environment at a higher temperature level and pressure level.

[0007] When an air conditioning system with a heat pump system or a refrigerant circuit of an air conditioning system is operated in heating mode, the heat required for evaporation of the refrigerant is absorbed from a heat source in the evaporator at a low temperature level and pressure level. Ambient air can be used as a heat source. The heat absorbed from the ambient air for evaporation of the refrigerant can be transferred directly to the refrigerant in a refrigerant / air heat exchanger, or first transferred to a coolant circulating in a coolant circuit, and then transferred from the coolant to the refrigerant in a refrigerant / coolant heat exchanger.

[0008] The performance and energy efficiency of an air conditioning system with a heat pump function depends in particular on the fact at which temperature level heat is available for evaporation of the refrigerant. At low ambient temperatures, the heat absorbed from the ambient air is also limited due to the need to avoid freezing of the surfaces of the heat exchanger filled with ambient air. Freezing of the surfaces of the heat exchanger reduces the heat transfer between the ambient air and the surfaces of the heat exchanger and thus reduces the heat exchange from the ambient air to the refrigerant, which reduces the heat transfer from the ambient air to the refrigerant and the energy efficiency of the entire air conditioning system.

[0009] Furthermore, the maximum temperature difference between the temperature of the ambient air flowing into the heat exchanger and the temperature of the refrigerant is limited. On the other hand, the maximum temperature difference has a limiting effect on the heat that can be transferred from the ambient air to the refrigerant.

[0010] At very low temperatures of the ambient air, freezing of the surfaces of the heat exchanger filled with ambient air cannot be avoided, so that if only ambient air is used as a heat source, the intake air for the passenger compartment cannot be sufficiently heated. In order to sufficiently heat the intake air for the passenger compartment at very low temperatures of the ambient air, the refrigerant circuit at the low-pressure side is formed with a refrigerant / coolant heat exchanger as a thermal connection of the refrigerant circuit to the coolant circuit, which is formed for controlling the temperature of components of the electric drive train of a motor vehicle. The coolant absorbs waste heat of, for example, at least one component of the electric drive train, such as a battery cell of a high-voltage battery. The refrigerant / coolant heat exchanger, also referred to as a refrigerator, enables an additional possible heat transfer from a coolant circulating in the coolant circuit, in particular a water / glycol mixture, to a refrigerant circulating in the refrigerant circuit. The heat transferred from the components of the electric drive train to the coolant can also be transferred directly to the environment, in particular the ambient air, in a so-called low-temperature heat exchanger of the coolant circuit without operating the refrigerant circuit.

[0011] Air conditioning systems known from the prior art with a heat pump function for heat distribution in battery-electrically driven motor vehicles are very complex in design and require multiple components both on the refrigerant and coolant side and on the air side, which leads to high system costs.

[0012] Motor vehicles with a large volume passenger compartment and therefore a large amount of intake air to be air conditioned, such as sports and utility vehicles, or off-road luxury sedans or SUVs, people carriers and large volume luxury sedans, referred to as VANs for short, require such high heating and cooling performances that it is difficult to provide air conditioning systems with heat pump functionality for other motor vehicles. In particular, there is a lack of adequate comfort for passengers in the rear section of the passenger compartment.

[0013] Conventional air conditioning systems of simple construction allow, for example, uncomplicated integration of one or more after-air conditioners, but can only be operated in an energy-inefficient manner. For air conditioning systems known from the prior art that can be operated in a more energy-efficient manner, in particular air conditioning systems having a heat exchanger charged with ambient air, the integration of one or more after-air conditioners is not easily achievable. However, such air conditioning systems that can be operated more efficiently do not have any refrigerant lines in which correctly regulated refrigerant is always provided for the additional after-air conditioner.

[0014] DE 10 2021 131 215A1 discloses a heat pump device for a battery-operated vehicle having a refrigerant circuit and a coolant circuit. The refrigerant circuit has a compressor, a heating condenser, a first expansion valve, an ambient heat exchanger, at least one evaporator with an associated second expansion valve, and a 3 / 2-way refrigerant valve arranged in parallel with the evaporator and having an expansion function, as well as a refrigerator and a refrigerant path formed as a bypass around the refrigerator. Between the heating condenser and the first expansion valve, a refrigerant path formed as a bypass around the ambient heat exchanger with a third expansion valve branches, which refrigerant path leads upstream of the refrigerator in the flow direction. Summary of the invention

[0015] Technical issues

[0016] The object of the invention is to provide a system for air conditioning the air of a particularly large-volume passenger compartment, in particular for a passenger compartment of a motor vehicle with a purely electric drive or a combined electric and internal combustion engine drive. The system achieves the possible comfort air conditioning of the passenger compartment with the greatest energy efficiency. The system should be able to operate in a reliable manner both at low ambient air temperatures and at high ambient air temperatures. The manufacturing, maintenance and operating costs of the system as well as the required installation space should be minimized.

[0017] Technical Solution

[0018] This object is achieved by the subject matter having the features of the independent claim. Further developments are described in the dependent claims.

[0019] This object is achieved by a system according to the invention for air conditioning the air of a passenger compartment, in particular also for heat exchange with components of an electric drive train of a motor vehicle. The system has a refrigerant circuit with a compressor, a first refrigerant / air heat exchanger operable as a condenser / gas cooler for heating the intake air of the passenger compartment, a refrigerant path with a second refrigerant / air heat exchanger operable as a condenser / gas cooler or evaporator for heat exchange with ambient air and with a first expansion member upstream, and a third refrigerant / air heat exchanger operable as an evaporator for conditioning the intake air of the passenger compartment and with a second expansion member upstream, and a refrigerant path with a first refrigerant / coolant heat exchanger operable as an evaporator for heat exchange between a coolant for controlling the temperature of at least one component of a preferably electric drive train of a motor vehicle and a refrigerant and with a third expansion member upstream.

[0020] The refrigerant path having the second and third refrigerant / air heat exchangers and the refrigerant path having the refrigerant / coolant heat exchanger operable as an evaporator extend from the branch point to the opening point, respectively. The refrigerant paths can be charged with refrigerant independently and in parallel with each other.

[0021] For example, if the liquefaction of the refrigerant occurs during subcritical operation, such as with the refrigerant R134a or during subcritical operation with carbon dioxide under certain ambient conditions, the heat exchanger is called a condenser. Part of the heat transfer is carried out at a constant temperature. During supercritical operation or supercritical heat release in the heat exchanger, the temperature of the refrigerant drops continuously. In this case, the heat exchanger is also called a gas cooler. Supercritical operation may occur under certain ambient conditions or operating modes of the refrigerant circuit, such as when using the refrigerant carbon dioxide.

[0022] For example, an electric motor, an internal charger, a transformer or an inverter are considered to be components of the electric drive train of a motor vehicle. Batteries, in particular high-voltage batteries, can also be considered to be components of the electric drive train.

[0023] According to the concept of the present invention, the refrigerant circuit has a connection point with a first port, a second port and a third port. The first port is arranged between the first expansion member of the first refrigerant / air heat exchanger and the second refrigerant / air heat exchanger, and the third port is arranged between the second expansion member of the second refrigerant / air heat exchanger and the third refrigerant / air heat exchanger. The following refrigerant path extends from the third port of the connection point to the opening point: in the refrigerant path, at least one refrigerant / air heat exchanger that can be operated as an evaporator for conditioning the intake air of the passenger compartment and has an upstream expansion member is formed. The opening point is arranged upstream of the compressor in the flow direction of the refrigerant.

[0024] According to another improvement of the present invention, the refrigerant path extending from the third port of the connection point to the opening point has a first flow path and a second flow path, the first flow path and the second flow path respectively extend from the branch point to the opening point, and can be charged with refrigerant independently and in parallel with each other. The first flow path is formed with a fourth refrigerant / air heat exchanger with an upstream fourth expansion member capable of operating as an evaporator, and the second flow path is formed with a fifth refrigerant / air heat exchanger with an upstream fifth expansion member capable of operating as an evaporator.

[0025] According to a preferred design of the present invention, a branch point of the refrigerant path having the second refrigerant / air heat exchanger and the third refrigerant / air heat exchanger on the one hand and the refrigerant path having the refrigerant / coolant heat exchanger capable of operating as an evaporator on the other hand is arranged between the first refrigerant / air heat exchanger and the first expansion member of the second refrigerant / air heat exchanger. The opening point of the refrigerant path having the second refrigerant / air heat exchanger and the third refrigerant / air heat exchanger and the refrigerant path having the refrigerant / coolant heat exchanger capable of operating as an evaporator is preferably arranged upstream of the compressor in the flow direction of the refrigerant.

[0026] According to an advantageous design of the invention, the connection point is formed as a 3 / 2-way valve, wherein the first port is the inlet, the second port is the outlet, and the third port is the inlet and the outlet. The 3 / 2-way valve can be connected via the first port to the outlet of a first refrigerant / air heat exchanger for heating the intake air of the passenger compartment and via the third port to the outlet of a second refrigerant / air heat exchanger for heat exchange with ambient air. The 3 / 2-way valve advantageously has a high internal tightness.

[0027] According to another preferred design of the present invention, the refrigerant circuit has an accumulator, which is arranged upstream of the compressor in the flow direction of the refrigerant, so that the refrigerant flowing out of the accumulator is directly sucked into the compressor. The opening point of the refrigerant path extending from the third port of the connection point can be arranged between the third refrigerant / air heat exchanger and the compressor, in particular, upstream of the accumulator in the flow direction of the refrigerant, or between the accumulator and the compressor.

[0028] A particular advantage of the present invention is that the refrigerant circuit has a connection point formed as a 3 / 2-way valve, the 3 / 2-way valve has an expansion function and has a first port, a second port and a third port. In particular, the first port is formed as an inlet, and the second port and the third port are formed as outlets, respectively, and the expansion function is formed between the first port and the third port of the 3 / 2-way valve. The 3 / 2-way valve with an expansion function can be connected via the first port to a branch point between a second expansion member arranged for heat exchange with ambient air and a third refrigerant / air heat exchanger for conditioning the intake air of the passenger compartment, via the second port to an opening point arranged between the third refrigerant / air heat exchanger and the compressor, and via the third port to an opening point arranged between the third expansion member and a refrigerant / coolant heat exchanger capable of operating as an evaporator.

[0029] According to another improvement of the present invention, the system has an air conditioner with at least two air flow channels. A third refrigerant / air heat exchanger operable as an evaporator for conditioning the incoming air of the passenger compartment and a first refrigerant / air heat exchanger operable as a condenser / gas cooler for heating the incoming air of the passenger compartment are preferably arranged one after another in the flow direction of the incoming air in the first air flow channel, which leads to the passenger compartment in the front section of the passenger compartment. A fourth refrigerant / air heat exchanger operable as an evaporator for conditioning the incoming air of the passenger compartment is preferably arranged in the second air flow channel, which leads to the passenger compartment in the rear section of the passenger compartment. A fifth refrigerant / air heat exchanger operable as an evaporator for conditioning the incoming air of the passenger compartment can be arranged in the third air flow channel, which leads to the passenger compartment in the rear section of the passenger compartment.

[0030] It is particularly advantageous if a respective heat exchanger for heating the intake air, which can be formed as a coolant / air heat exchanger or an electric PTC heater, is arranged in the respective air flow channel in the flow direction of the intake air downstream of the refrigerant / air heat exchanger which can be operated as an evaporator.

[0031] According to another advantageous design of the invention, the refrigerant circuit has a refrigerant / coolant heat exchanger that can be operated as a condenser / gas cooler and a branch point that is formed as a 3 / 2-way valve with a first port, a second port and a third port. In particular, the first port is formed as an inlet and the second port and the third port are each formed as an outlet.

[0032] The 3 / 2-way valve can be connected via a first port to the outlet of the compressor, via a second port to a refrigerant / coolant heat exchanger capable of operating as a condenser / gas cooler, and via a third port to an opening point arranged upstream of the first refrigerant / air heat exchanger in the flow direction of the refrigerant.

[0033] The refrigerant / coolant heat exchanger operable as a condenser / gas cooler is preferably arranged within a flow path extending between the second port of the 3 / 2-way valve to an opening point arranged upstream of the first refrigerant / air heat exchanger.

[0034] Preferably, the 3 / 2-way valve is electrically driven.The expansion members are each advantageously formed as an expansion valve.

[0035] The refrigerant / coolant heat exchanger operable as an evaporator and the refrigerant / coolant heat exchanger operable as a condenser / gas cooler can be formed as parts of a common coolant circuit or of separate coolant circuits. The partial coolant circuits can also be operated together as a coolant circuit, or independently and completely separated fluidically from each other, wherein a complete partial amount of coolant is associated with each of the partial refrigerant circuits.

[0036] The object is also achieved by a first method according to the invention for operating the above-described system for air conditioning the air of the passenger compartment of a motor vehicle in a refrigeration device mode for conditioning, in particular cooling and / or dehumidifying, the intake air of the passenger compartment. The method comprises the following steps:

[0037] - directing the refrigerant circulating in the refrigerant circuit and flowing out of the compressor at a high pressure level through the first expansion member to the second refrigerant / air heat exchanger operating as a condenser / gas cooler, and transferring heat from the refrigerant at a high pressure level to the ambient air, wherein the first expansion member is fully opened and the refrigerant is fully liquefied and subcooled or cooled while flowing through the second refrigerant / air heat exchanger,

[0038] - directing the refrigerant flowing out of the second refrigerant / air heat exchanger to a connection point formed as a 3 / 2-way valve, and

[0039] - dividing the refrigerant into a partial mass flow through a third refrigerant / air heat exchanger operating as an evaporator with a second expansion member upstream and a partial mass flow through a refrigerant path extending from the third port of the 3 / 2-way valve to the opening point, the refrigerant path having at least one refrigerant / air heat exchanger operating as an evaporator with an expansion member upstream,

[0040] - relaxing the partial mass flow to a low pressure level when it flows through the expansion member and directing the partial mass flow to a refrigerant / air heat exchanger operating as an evaporator,

[0041] - evaporating and optionally superheating the partial mass flow when it flows through a refrigerant / air heat exchanger operating as an evaporator, wherein corresponding heat is transferred from intake air of the passenger compartment guided through the air flow channel to the refrigerant, wherein the intake air is cooled and / or dehumidified and flows out of the air flow channel into a front section of the passenger compartment and into a rear section of the passenger compartment, respectively, and

[0042] A partial mass flow of the refrigerant is mixed upstream of the compressor in the flow direction of the refrigerant and the refrigerant is sucked in through the compressor.

[0043] According to another improvement of the present invention, a partial mass flow of the refrigerant guided through the refrigerant path extending from the third port of the 3 / 2-way valve to the opening point is divided into a partial mass flow through the first flow path and a partial mass flow through the second flow path. The partial mass flow flowing through the first flow path and the partial mass flow flowing through the second flow path are respectively relaxed to a low pressure level when flowing through the expansion member, and are evaporated and optionally superheated when flowing through the refrigerant / air heat exchanger. Heat is transferred to the refrigerant from the intake air of the passenger compartment guided through one of the air flow channels, respectively, wherein the intake air is cooled and / or dehumidified and flows out of the air flow channel into the rear section of the passenger compartment. The partial mass flows of the vaporous and optionally superheated refrigerant are then mixed with each other.

[0044] According to a preferred design of the present invention, the refrigerant flowing out of the second refrigerant / air heat exchanger is divided into a partial mass flow leading to a connection point formed as a 3 / 2-way valve and a partial mass flow leading to a 3 / 2-way valve with an expansion function. The partial mass flow directed to the 3 / 2-way valve with an expansion function is relaxed to a low pressure level when flowing through the 3 / 2-way valve, and is evaporated and optionally superheated when flowing through the refrigerant / coolant heat exchanger operating as an evaporator. In doing so, heat is transferred from the coolant circulating in the coolant circuit to the refrigerant circulating in the refrigerant circuit. The partial mass flows of the refrigerants are mixed with each other before being sucked into the compressor.

[0045] The cooled coolant is advantageously delivered to at least one component of the drive train, and this component is thereby cooled.

[0046] The refrigerant flowing out of the compressor at a high pressure level can be directed to a refrigerant / coolant heat exchanger operating as a condenser / gas cooler. When flowing through the refrigerant / coolant heat exchanger, the refrigerant is preferably at least deheated and partially liquefied or cooled. In doing so, heat is transferred from the refrigerant to the coolant circulating in the coolant circuit.

[0047] The object is also achieved by a second method according to the invention for operating the above-described system for air conditioning the air of the passenger compartment of a motor vehicle in a post-heating mode for conditioning, in particular dehumidifying and optionally cooling and post-heating the intake air of the passenger compartment. The method has the following steps:

[0048] - directing the refrigerant circulating in the refrigerant circuit and flowing out of the compressor at a high pressure level to a refrigerant / coolant heat exchanger operating as a condenser / gas cooler and transferring heat from the refrigerant to the coolant circulating in the coolant circuit, wherein the refrigerant is at least deheated and partially liquefied or cooled while flowing through the refrigerant / coolant heat exchanger (28), wherein the heated coolant is directed through a heat exchanger charged with intake air for heating previously dehumidified and optionally cooled intake air of a rear section of the passenger compartment,

[0049] - directing the refrigerant flowing out of the refrigerant / coolant heat exchanger operating as a condenser / gas cooler to a first refrigerant / air heat exchanger and transferring heat from the refrigerant at a high pressure level to the intake air for the front section of the passenger compartment, wherein the refrigerant is completely liquefied and supercooled or cooled while flowing through the first refrigerant / air heat exchanger, and the previously dehumidified and optionally cooled intake air is heated,

[0050] - directing the refrigerant flowing out of the first refrigerant / air heat exchanger to a connection point formed as a 3 / 2-way valve, and

[0051] - dividing the refrigerant into a partial mass flow through a second refrigerant / air heat exchanger operating as an evaporator with a first expansion member upstream and a partial mass flow through a refrigerant path extending from a third port formed as a connection point of a 3 / 2-way valve to an opening point, the refrigerant path having at least one refrigerant / air heat exchanger operating as an evaporator with an expansion member upstream,

[0052] - relaxing a part of the mass flow of the refrigerant directed to the second refrigerant / air heat exchanger to an intermediate pressure level or a low pressure level when flowing through the first expansion member, and directing the part of the mass flow through the second refrigerant / air heat exchanger operating as an evaporator, wherein the refrigerant at least partially evaporates and heat is transferred from the ambient air to the refrigerant, and directing the part of the mass flow of the refrigerant flowing out of the second refrigerant / air heat exchanger to a third refrigerant / air heat exchanger operating as an evaporator with an upstream second expansion member, and relaxing the part of the mass flow to a low pressure level when flowing through the second expansion member, and directing the part of the mass flow to the third refrigerant / air heat exchanger operating as an evaporator,

[0053] - a part of the mass flow of the refrigerant which is directed through a refrigerant path extending from a third port of a connection point formed as a 3 / 2-way valve to an opening point, the refrigerant path having at least one refrigerant / air heat exchanger operating as an evaporator having said expansion member, is relaxed to a low pressure level when flowing through an upstream expansion member, and the part of the mass flow is directed to the refrigerant / air heat exchanger operating as an evaporator,

[0054] - evaporating and optionally superheating a partial mass flow of the refrigerant when it flows through the refrigerant / air heat exchanger operating as an evaporator, wherein corresponding heat is transferred to the refrigerant from intake air of the passenger compartment guided through the air flow channel, wherein the intake air is cooled and / or dehumidified, wherein the intake air flowing through the first refrigerant / air heat exchanger is heated and flows out into a front section of the passenger compartment, and the intake air flowing through the heat exchanger is heated and flows out into a rear section of the passenger compartment, and

[0055] - A partial mass flow of refrigerant is mixed and drawn in through the compressor.

[0056] According to another improvement of the present invention, a partial mass flow of the refrigerant guided through a refrigerant path extending from a third port of a connection point formed as a 3 / 2-way valve to an opening point is divided into a partial mass flow through a first flow path and a partial mass flow through a second flow path. The partial mass flow flowing through the first flow path and the partial mass flow flowing through the second flow path are respectively relaxed to a low pressure level when flowing through an expansion member, and are evaporated and optionally superheated when flowing through a refrigerant / air heat exchanger. Heat is transferred to the refrigerant from the intake air of the passenger compartment guided through one of the air flow channels, respectively, wherein the intake air is cooled and / or dehumidified, and is heated when flowing through the heat exchanger and flows out of the air flow channel into a rear section of the passenger compartment. The partial mass flows of the vaporous and optionally superheated refrigerant are mixed with each other.

[0057] According to an advantageous design of the invention, the partial mass flow of the refrigerant directed to the second refrigerant / air heat exchanger with the first expansion member upstream, which operates as an evaporator, is divided into a partial mass flow to the first expansion member and a partial mass flow to the refrigerant / coolant heat exchanger with the third expansion member upstream, which operates as an evaporator. The partial mass flow directed to the refrigerant / coolant heat exchanger operating as an evaporator is relaxed to a low pressure level when flowing through the third expansion member, and is evaporated and optionally superheated when flowing through the refrigerant / coolant heat exchanger. In doing so, heat is transferred from the coolant circulating in the coolant circuit to the refrigerant circulating in the refrigerant circuit. The partial mass flows of the refrigerants are mixed with each other before being sucked in by the compressor.

[0058] The cooled coolant is advantageously delivered to at least one component of the drive train, and this component is cooled.

[0059] An advantageous embodiment of the invention enables the system to be used in a motor vehicle having an electric motor drive or a hybrid drive having an electric motor and an internal combustion engine.

[0060] The system according to the invention can advantageously be operated so that the refrigerant is always directed to an expansion member upstream of a refrigerant / air heat exchanger, which in particular operates as an evaporator in an optimal state, in order to dehumidify or dry and cool the intake air of the passenger compartment. The refrigerant is advantageously mostly in a supercooled or at least completely or partially liquid state, resting against the expansion member at a high pressure level, in particular at a high pressure level or a medium pressure level. The refrigerant / air heat exchanger, which operates as an evaporator and has an upstream expansion element, which is specifically arranged in an air flow channel or in at least two air flow channels leading to the rear section of the passenger compartment, respectively, can be connected to the outlet of a first refrigerant / air heat exchanger, which can be operated as a condenser / gas cooler, for heating the intake air of the passenger compartment, or to the outlet of a second refrigerant / air heat exchanger for heat exchange with ambient air, depending on requirements and operating mode.

[0061] Advantageous Effects of the Invention

[0062] In summary, in particular for motor vehicles with pure electric drive or hybrid drive with an internal combustion engine, the system according to the invention with an integrated heat pump function has several advantages:

[0063] - meets all requirements for thermal management of electric vehicles over a very wide range of ambient temperatures by air conditioning the air in the passenger compartment by cooling, dehumidifying and heating and controlling the temperature, in particular cooling or heating the battery and cooling components of the powertrain,

[0064] - A high degree of waste heat recovery, thus energy-efficient heating of the intake air for the passenger compartment by using waste heat from the refrigerant circuit and recovering heat from components of the electric drive train, thereby

[0065] - maximum energy efficiency during operation, in particular high energy efficiency during operation in an ambient temperature range between 5° C. and 35° C., with a high degree of waste heat utilization and high flexibility and functionality, and thus minimum energy consumption, in particular minimum electrical energy consumption, which, for example, maximizes the range of an electrically driven motor vehicle or reduces the size of the battery compared to motor vehicles with a similar range,

[0066] - maximum comfort in the entire passenger compartment, even in the case of larger air volumes, such as for motor vehicles with more than five passengers,

[0067] - a compact design with little complexity both on the refrigerant side and on the air side, in particular by minimizing the total refrigerant requirement of the system by using suitable refrigerant lines with corresponding flow cross sections,

[0068] - Low costs for production and maintenance as well as during operation are achieved, in particular also by using simple, cost-effective expansion members associated with the refrigerant / air heat exchanger.

[0069] The system, in particular the refrigerant circuit, is independent of the refrigerant used and is therefore also suitable for R134a, R1234yf, R290 or other refrigerants. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Other details, features and advantages of the design of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings, in which:

[0071] Figure 1a : a first system for air conditioning air in a passenger compartment of a motor vehicle using a first refrigerant circuit, and

[0072] Figure 1b : a second system for air conditioning the air of a passenger compartment of a motor vehicle using a second refrigerant circuit,

[0073] Figure 2 : The refrigerant circuit during operation in the first refrigeration equipment mode Figure 1a The first system,

[0074] Figure 3 : The refrigerant circuit during operation in the second refrigeration equipment mode Figure 1a The first system,

[0075] Figure 4 : Refrigerant circuit during operation in post-heating mode Figure 1a The first system, and

[0076] Figure 5 : The refrigerant circuit during operation in the first heating mode Figure 1a The first system. DETAILED DESCRIPTION

[0077] Figure 1a and Figure 1b A system 1 - 1 , 1 - 2 for air conditioning the air of a passenger compartment of a motor vehicle using a refrigerant circuit 2 - 1 , 2 - 2 , respectively, is shown.

[0078] The refrigerant circuits 2-1, 2-2, respectively indicated by double lines, have, in the flow direction of the refrigerant, a compressor 3 for sucking and compressing the refrigerant, a first refrigerant / air heat exchanger 4 operating as a condenser / gas cooler for heating the intake air of the passenger compartment, a second refrigerant / air heat exchanger 5 for heat exchange with the ambient air, and a first expansion member 6, in particular an expansion valve, located upstream of the second refrigerant / air heat exchanger 5. The refrigerant circuits 2-1, 2-2 are also respectively formed with a third refrigerant / air heat exchanger 7 operating as an evaporator for cooling or dehumidifying the intake air of the passenger compartment, and a second expansion member 8, in particular an expansion valve, located upstream of the third refrigerant / air heat exchanger 7. The outlet of the third refrigerant-air heat exchanger 7 is connected to the compressor 3. The refrigerant circuits 2-1, 2-2 are closed.

[0079] The third refrigerant / air heat exchanger 7 operating as an evaporator for cooling or dehumidifying the intake air of the passenger compartment and the first refrigerant / air heat exchanger 4 operating as a condenser / gas cooler for heating the intake air of the passenger compartment are arranged one after another in the stated order along the flow direction of the intake air in the first air flow passage 60 of the air conditioner of the motor vehicle. The intake air guided through the first air flow passage 60 can be introduced into the passenger compartment, particularly in the front section of the passenger compartment.

[0080] In case the first expansion member 6 is arranged between the first refrigerant / air heat exchanger 4 and the second refrigerant / air heat exchanger 5 through which the refrigerant flows at a high pressure level, the pressure level of the refrigerant in the second refrigerant / air heat exchanger 5 can be set to a pressure level in the range from the high pressure level up to the low pressure level for heat exchange from the refrigerant to the ambient air when operating in the refrigeration device mode, or for heat exchange from the ambient air to the refrigerant when operating in the heating mode. Thus, the system can be operated at three different pressure levels, wherein the medium pressure level can be varied between the high pressure level and the low pressure level, also referred to as the suction pressure level of the compressor 3. For example, by varying the medium pressure level of the refrigerant in the second refrigerant / air heat exchanger 5, on the one hand, when operating the system 1-1, 1-2 in the refrigeration device mode, the heat dissipation from the refrigerant to the ambient air can be limited or regulated, and on the other hand, when operating the system 1-1, 1-2 in the heating mode, the heat absorption from the ambient air can be regulated.

[0081] The refrigerant circuits 2-1, 2-2 also each have a first refrigerant / coolant heat exchanger 9 operating as an evaporator, wherein in the flow direction of the refrigerant, a third expansion member 10 is located upstream of the first refrigerant / coolant heat exchanger 9 as a thermal connection to at least one refrigerant circuit. The first refrigerant / coolant heat exchanger 9 and the third expansion member 10, in particular the expansion valve, are arranged in a refrigerant path extending from a first branch point 11 to a first opening point 12. The first branch point 11 is arranged between the first expansion member 6 of the first refrigerant / air heat exchanger 4 and the second refrigerant / air heat exchanger 5, while the first opening point 12 is arranged between the third refrigerant / air heat exchanger 7 and the compressor 3.

[0082] Therefore, as an alternative to flowing through the second refrigerant / air heat exchanger 5 and the third refrigerant / air heat exchanger 7 with the second expansion member 8 operating as an evaporator, the first refrigerant / air heat exchanger 4 is also connected to the compressor 3 via the third expansion member 10 and the first refrigerant / coolant heat exchanger 9. The refrigerant path with the first refrigerant / coolant heat exchanger 9 and the third expansion member 10 is formed in parallel with the refrigerant path with the second refrigerant / air heat exchanger 5 and the third refrigerant / air heat exchanger 7 with the respective upstream expansion members 6, 8.

[0083] In addition, the outlet of the second refrigerant / air heat exchanger 5 is connected to the second expansion member 8 of the third refrigerant / air heat exchanger 7, and is also connected to the first 3 / 2-way valve 13 having an expansion function. The first 3 / 2-way valve 13 has three ports 13a, 13b, 13c. The first port 13a is formed as the inlet of the first 3 / 2-way valve 13, and the second port 13b and the third port 13c are respectively formed as the outlets of the first 3 / 2-way valve 13. When flowing from the first port 13a to the third port 13c, the expansion function of the first 3 / 2-way valve 13 is provided. The first 3 / 2-way valve 13 is connected to the second refrigerant / air heat exchanger 5 via the first port 13a, to the compressor 3 via the second port 13b, and to the first refrigerant / coolant heat exchanger 9 via the third port 13c.

[0084] The first port 13a of the first 3 / 2-way valve 13 is connected as an inlet to a second branch point 14 arranged between the second refrigerant / air heat exchanger 5 and the second expansion member 8 of the third refrigerant / air heat exchanger 7 operating as an evaporator. The second port 13b of the first 3 / 2-way valve 13 is connected as an outlet to a second opening point 15 formed between the third refrigerant / air heat exchanger 7 and the first opening point 12 or the compressor 3. The third port 13c of the first 3 / 2-way valve 13 is connected as an outlet to a third opening point 16 arranged between the third expansion member 10 of the first refrigerant / coolant heat exchanger 9 and the first refrigerant / coolant heat exchanger 9 operating as an evaporator.

[0085] Thus, although the first 3 / 2-way valve 13 can be fluidly connected to the first refrigerant / coolant heat exchanger 9 via the third port 13c having an expansion function as an outlet, the third port 13c as an outlet can be directly fluidly connected to the suction side of the refrigerant circuit 2-1, 2-2, and thus can be directly fluidly connected to the bypass flow path around the first refrigerant / coolant heat exchanger 9 and the third refrigerant / air heat exchanger 7 having the associated second expansion member 8. Instead of the first 3 / 2-way valve 13 having an expansion function, respective valves having corresponding functions can also be adopted as an alternative.

[0086] In addition, the refrigerant circuits 2-1, 2-2 each have an accumulator 17 connected at the outlet to the suction side of the compressor 3. The suction-side refrigerant lines from the outlets of the third refrigerant / air heat exchanger 7 and the first refrigerant / coolant heat exchanger 9, respectively, which operate as evaporators, and the second port 13b of the first 3 / 2-way valve 13 are connected to each other via the first opening point 12 and the second opening point 15 upstream of the inlet of the accumulator 17. Therefore, when the refrigerant flows through the second refrigerant / air heat exchanger 5, the third refrigerant / air heat exchanger 7 arranged in the first air flow passage 60 of the air conditioner, and the first refrigerant / coolant heat exchanger 9, respectively, the refrigerant may be partially evaporated, vaporized, or overheated.

[0087] The refrigerant circuits 2-1, 2-2 enable the second refrigerant / air heat exchanger 5 and the first refrigerant / coolant heat exchanger 9 to be operated in parallel at different pressure levels of the refrigerant. If necessary, the second refrigerant / air heat exchanger 5 and the first refrigerant / coolant heat exchanger 9 can also be operated so that the refrigerant flows through them continuously. The operating mode can be flexibly adapted to ambient conditions or operating conditions, such as the temperature of the motor vehicle and the available heat source.

[0088] The refrigerant circuits 2-1, 2-2 also have a fourth refrigerant / air heat exchanger 18 operating as an evaporator and a fifth refrigerant / air heat exchanger 20 operating as an evaporator, respectively, and a fourth expansion member 19 located upstream of the fourth refrigerant / air heat exchanger 18 and a fifth expansion member 21 located upstream of the fifth refrigerant / air heat exchanger 20, respectively, for cooling or dehumidifying the intake air of the rear section of the passenger compartment. The fourth refrigerant / air heat exchanger 18 having the fourth expansion member 19 is arranged in a first flow path 22, and the fifth refrigerant / air heat exchanger 20 having the fifth expansion member 21 is arranged in a second flow path 23, the first flow path 22 and the second flow path 23 respectively extend from a third branch point 24 to a fourth opening point 25 and can be filled with refrigerant in parallel. The fourth opening point 25 is connected to the fifth opening points 26-1, 26-2 via a refrigerant line. Figure 1a The fifth opening point 26-1 of the refrigerant circuit 2-1 of the system 1-1 is arranged between the third refrigerant / air heat exchanger 7 and the compressor 3, in particular, arranged upstream of the accumulator 17 along the flow direction of the refrigerant, specifically arranged between the second opening point 15 and the first opening point 12, and Figure 1b The fifth opening point 26-2 of the refrigerant circuit 2-2 of the system 1-2 is arranged between the outlet of the accumulator 17 and the inlet of the compressor 3. In particular, the fourth expansion member 19 and the fifth expansion member 21 are respective expansion valves. The expansion members 6, 8, 10, 19, 21 can be respectively formed as expansion valves that can be closed.

[0089] The third branch point 24 is connected to a second 3 / 2-way valve 27 formed as a connection point via a refrigerant line. The second 3 / 2-way valve 27 has three ports 27a, 27b, 27c. The first port 27a is formed as an inlet of the second 3 / 2-way valve 27, the second port 27b is formed as an outlet of the second 3 / 2-way valve 27, and the third port 27c is formed as an inlet and an outlet of the second 3 / 2-way valve 27. The first port 27a of the second 3 / 2-way valve 27 is arranged as an inlet between the first refrigerant / air heat exchanger 4 operating as a condenser / gas cooler and the first expansion member 6 of the second refrigerant / air heat exchanger 5, in particular the first branch point 11, while the second port 27b of the second 3 / 2-way valve 27 is connected to the third branch point 24 as an outlet. The third port 27c of the second 3 / 2-way valve 27, which is used as an inlet or an outlet according to the operating mode, is arranged between the second refrigerant / air heat exchanger 5, in particular the second branch point 14, and the second expansion member 8 of the third refrigerant / air heat exchanger 7.

[0090] In this way, as an alternative, the first refrigerant / air heat exchanger 4 can be connected to the fourth refrigerant / air heat exchanger 18 or the fifth refrigerant / air heat exchanger 20 via the first port 27a as the inlet and the second port 27b as the outlet through the second 3 / 2-way valve 27, and the second refrigerant / air heat exchanger 5 can also be connected to the fourth refrigerant / air heat exchanger 18 or the fifth refrigerant / air heat exchanger 20 via the third port 27c as the inlet and the second port 27b as the outlet through the second 3 / 2-way valve 27. Instead of the second 3 / 2-way valve 27, a separate shut-off valve can also be used as an alternative.

[0091] The refrigerant circuits 2-1, 2-2 also have a second refrigerant / coolant heat exchanger 28, respectively, which operates as a condenser / gas cooler and is arranged upstream of the first refrigerant / air heat exchanger 4, which also operates as a condenser / gas cooler, in the flow direction of the refrigerant, and is therefore arranged between the compressor 3 and the first refrigerant / air heat exchanger 4. In the second refrigerant / coolant heat exchanger 28, heat is transferred from the refrigerant circulating in the refrigerant circuits 2-1, 22 to the coolant circulating in the coolant circuit. The second refrigerant / coolant heat exchanger 28 can be formed as a thermal connection of the refrigerant circuits 2-1, 2-2 with a coolant circuit in which the first refrigerant / coolant heat exchanger 9 is also combined. Alternatively, the second refrigerant / coolant heat exchanger 28 can also represent a thermal connection of the refrigerant circuits 2-1, 2-2 with a second coolant circuit, which is different from the first coolant circuit having the first refrigerant / coolant heat exchanger 9.

[0092] One or more coolant circuits are used for temperature control, in particular for cooling or heating the battery or components of the electric drive train, and for air conditioning the passenger compartment, in particular for heating the intake air of the passenger compartment.

[0093] A respective third 3 / 2-way valve 29 having three ports 29a, 29b, 29c formed as branch points is arranged between the compressor 3 and the second refrigerant / coolant heat exchanger 28 in the refrigerant circuit 2-1, 2-2. The first port 29a is formed as an inlet of the third 3 / 2-way valve 29, and the second port 29b and the third port 29c are formed as outlets of the third 3 / 2-way valve 29, respectively. The first port 29a of the third 3 / 2-way valve 29 is connected to the outlet of the compressor 3 as an inlet, and the second port 29b of the second 3 / 2-way valve 27 is connected to the second refrigerant / coolant heat exchanger 28 as an outlet. The second refrigerant / coolant heat exchanger 28 is arranged in a flow path extending between the third 3 / 2-way valve 29 as a branch point to a sixth opening point 30. The sixth opening point 30 is formed upstream of the inlet of the first refrigerant / air heat exchanger 4 in the flow direction of the refrigerant.

[0094] The third 3 / 2-way valve 29 is also connected to the sixth opening point 30 via the third port 29c, so that a bypass flow path around the second refrigerant / coolant heat exchanger 28 is provided between the third port 29c of the third 3 / 2-way valve 29 and the sixth opening point 30. When the bypass flow path is filled with refrigerant, in order to prevent the refrigerant from flowing back to the second refrigerant / coolant heat exchanger 28 at the sixth opening point 30, a return device 31, in particular a return valve, is arranged in the flow path with the second refrigerant / coolant heat exchanger 28. Instead of the third 3 / 2-way valve 29, a separate shut-off valve can also be used as an alternative.

[0095] In addition to the respective refrigerant circuit 2-1, 2-2, the system 1-1, 1-2 has a heat exchanger 50, 51, 52 for heating the intake air flowing into the passenger compartment, which heat exchanger 50, 51, 52 can each be formed as a refrigerant / air heat exchanger and thus as a component of a coolant circuit, in particular one coolant circuit or a first coolant circuit or a second coolant circuit. In addition, an additional heat exchanger 53 formed as an electric PTC heater can be provided.

[0096] The first heat exchanger 50 is arranged in a first air flow passage 60 of an air conditioner of a motor vehicle together with the third refrigerant / air heat exchanger 7 operating as an evaporator for cooling or dehumidifying the intake air of the passenger compartment and the first refrigerant / air heat exchanger 4 operating as a condenser / gas cooler for heating the intake air of the passenger compartment. The first heat exchanger 50 is positioned downstream of the first refrigerant / air heat exchanger 4 in the flow direction of the intake air of the passenger compartment.

[0097] Furthermore, a second heat exchanger 51 for heating the intake air of the rear section of the passenger compartment is arranged in the second air flow passage 61 of the air conditioner of the motor vehicle adjacent to the fourth refrigerant / air heat exchanger 18 operating as an evaporator for cooling or dehumidifying the intake air of the rear section of the passenger compartment, and a third heat exchanger 52 for heating the intake air of the rear section of the passenger compartment is arranged in the third air flow passage 62 of the air conditioner adjacent to the fifth refrigerant / air heat exchanger 20 operating as an evaporator for cooling or dehumidifying the intake air of the rear section of the passenger compartment. The heat exchangers 51, 52 are respectively positioned downstream of the refrigerant / air heat exchangers 18, 20 in the flow direction of the intake air of the passenger compartment.

[0098] If not enough heat is transferred to the coolant in the second refrigerant / coolant heat exchanger 28 , the additional heat exchanger 53 is used to heat the coolant of the coolant circuit in which the second heat exchanger 51 and the third heat exchanger 52 are combined.

[0099] The refrigerant circuits 2-1, 2-2 are formed with different sensors, in particular pressure / temperature sensors 41, 42 and temperature sensors 43, 44, respectively. The first pressure / temperature sensor 41 is arranged at the outlet of the compressor 3 in order to determine the high pressure and outlet temperature of the refrigerant on the compressor 3. The second pressure / temperature sensor 42 is arranged downstream of the third refrigerant / air heat exchanger 7 operating as an evaporator in the flow direction of the refrigerant in order to determine the low pressure and outlet temperature of the refrigerant at the third refrigerant / air heat exchanger 7, and thus determine the refrigerant superheat. The first temperature sensor 43 is arranged at the outlet of the first refrigerant / air heat exchanger 4, and the second temperature sensor 44 is arranged at the outlet of the first refrigerant / coolant heat exchanger 9 operating as an evaporator.

[0100] In the following, the Figure 1a 1-1 of the refrigerant circuit 2-1 of the system 1-1. The active components of the refrigerant circuit 2-1 are connected to each other via the highlighted connection lines. In contrast to the active components, the inactive components are shown via the sparsely represented connection lines. No refrigerant flows through the sparsely represented connection lines.

[0101] The regions of the refrigerant circuit 2-1 through which refrigerants at different pressure levels flow are distinguished from each other by double solid lines and double dashed lines. The double solid lines show the regions of the refrigerant circuit 2-1 through which refrigerants at high pressure levels flow, while the double dashed lines show the regions of the refrigerant circuit 2-1 through which refrigerants at low pressure levels flow.

[0102] When operating in the first refrigeration equipment mode with Figure 1a The first system 1-1 of the refrigerant circuit 2-1 is used to Figure 2 When cooling and / or dehumidifying the intake air of the passenger compartment, the first port 29a of the third 3 / 2-way valve 29 is connected to the second port 29b, so that the refrigerant flowing out of the compressor 3 at a high pressure level is directed to the second refrigerant / coolant heat exchanger 28 operating as a condenser / gas cooler. When flowing through the second refrigerant / coolant heat exchanger 28, the refrigerant is at least deheated and partially liquefied or cooled. Heat is transferred from the refrigerant to the coolant circulating in the coolant circuit.

[0103] The refrigerant then flows through the return device 31 and the first refrigerant / air heat exchanger 4, which is not filled with the incoming air and is arranged in the first air flow passage 60 of the air conditioner, thereby flowing to the first expansion member 6 and the second refrigerant / air heat exchanger 5, which operates as a condenser / gas cooler. The first expansion member 6 is fully opened, so that the refrigerant at a high pressure level flows into the second refrigerant / air heat exchanger 5. When flowing through the second refrigerant / air heat exchanger 5, the refrigerant is completely liquefied and is supercooled or cooled. Heat is transferred from the refrigerant to the ambient air. In addition to the second refrigerant / air heat exchanger 5, the second refrigerant / coolant heat exchanger 28 is also used for additional heat dissipation from the refrigerant.

[0104] The supercooled refrigerant flowing out of the second refrigerant / air heat exchanger 5 is divided at the second branch point 14 into a first partial mass flow to the first 3 / 2-way valve 13 with an expansion function and a second partial mass flow to the second 3 / 2-way valve 27. The first partial mass flow of the refrigerant is relaxed to a low pressure level when flowing through the first 3 / 2-way valve 13 from the first port 13a formed as an inlet to the third port 13c formed as an outlet, and is then directed to the first refrigerant / coolant heat exchanger 9. The third expansion member 10 is closed. When flowing through the first refrigerant / coolant heat exchanger 9, the refrigerant is evaporated and optionally superheated. Heat is transferred from the coolant circulating in the coolant circuit to the refrigerant circulating in the refrigerant circuit 21. The coolant can be used for active cooling of the battery of the motor vehicle.

[0105] The third partial mass flow of the refrigerant branches off in the region of the second 3 / 2-way valve 27 from the second partial mass flow which is directed to the second 3 / 2-way valve 27. The second partial mass flow is relaxed to a low pressure level when flowing through the second expansion member 8 and is then directed to the third refrigerant / air heat exchanger 7. The second partial mass flow of the refrigerant which passes through the third refrigerant / air heat exchanger 7 which operates as an evaporator is regulated by means of the second expansion member 8.

[0106] When flowing through the third refrigerant / air heat exchanger 7, the refrigerant is evaporated and optionally superheated. Heat is transferred from the intake air of the passenger compartment guided through the first air flow channel 60 to the refrigerant circulating in the refrigerant circuit 21. The intake air is cooled and optionally dehumidified and then flows out into the front section of the passenger compartment. The first partial mass flow and the second partial mass flow of the refrigerant are mixed with each other at the first opening point 12 and introduced into the accumulator 17.

[0107] The third partial mass flow of the refrigerant is directed from the third port 27c operated as an inlet to the second port 27b formed as an outlet of the second 3 / 2-way valve 27 within any pressure change. Then, the fourth partial mass flow of the subcooled refrigerant at a high pressure level branches from the third partial mass flow at the third branch point 24. The third partial mass flow of the refrigerant flowing through the first flow path 22 is relaxed to a low pressure level when flowing through the fourth expansion member 19 and is directed to the fourth refrigerant / air heat exchanger 18, while the fourth partial mass flow of the refrigerant flowing through the second flow path 23 is relaxed to a low pressure level when flowing through the fifth expansion member 21 and is directed to the fifth refrigerant / air heat exchanger 20. The third partial mass flow and the fourth partial mass flow of the refrigerant are directed through the flow paths 22, 23 in parallel. The third partial mass flow of the refrigerant through the fourth refrigerant / air heat exchanger 18 operated as evaporator and the fourth partial mass flow of the refrigerant through the fifth refrigerant / air heat exchanger 20 operated as evaporator are correspondingly adjusted by means of the fourth expansion member 19 and the fifth expansion member 21 .

[0108] When flowing through the fourth refrigerant / air heat exchanger 18 and the fifth refrigerant / air heat exchanger 20, the refrigerant is evaporated and optionally superheated, respectively. Heat is transferred from the intake air of the passenger compartment guided through the second air flow passage 61 and the third air flow passage 62, respectively, to the refrigerant circulating in the refrigerant circuit 2-1. The intake air is cooled and optionally dehumidified, respectively, and then flows out to the rear section of the passenger compartment. The third partial mass flow and the fourth partial mass flow of the refrigerant are mixed with each other at the fourth opening point 25 and are guided to the fifth opening point 26-1 as the third partial mass flow. At the fifth opening point 26-1, the third partial mass flow is mixed with the second partial mass flow, and then the mixed third partial mass flow is guided to the first opening point 12 as the second partial mass flow with the second partial mass flow, and is mixed with the first partial mass flow at the first opening point 12, and flows into the accumulator 17. The evaporator 3 sucks the refrigerant from the accumulator 17.

[0109] When operating in the second refrigeration unit mode Figure 1a The first system 1-1 of the refrigerant circuit 2-1 is used to Figure 3When cooling and / or dehumidifying the passenger compartment intake air, Figure 2 Compared to the operation in the first refrigeration equipment mode of the present invention, the first port 29a of the third 3 / 2-way valve 29 is connected to the third port 29c, so that the refrigerant flowing out of the compressor 3 at a high pressure level is directly directed to the first refrigerant / air heat exchanger 4 that is not charged with incoming air. The refrigerant is directed to the first expansion member 6 and the second refrigerant / air heat exchanger 5 operating as a condenser / gas cooler through the first refrigerant / air heat exchanger 4. The first expansion member 6 is fully opened so that the refrigerant at a high pressure level flows into the second refrigerant / air heat exchanger 5. When flowing through the second refrigerant / air heat exchanger 5, the refrigerant is deheated, fully liquefied and optionally subcooled or cooled. Heat is transferred from the refrigerant to the ambient air. The second refrigerant / coolant heat exchanger 28 is not charged with refrigerant.

[0110] In addition, the operation of the first system 1-1 having the refrigerant circuit 2-1 in the second refrigeration equipment mode corresponds to Figure 2 The operation of the first system 1-1 having the refrigerant circuit 2-1 in the first refrigeration device mode is described with reference to Figure 2 explanation.

[0111] Figure 4 1 shows the refrigerant circuit 2-1 during operation in a post-heating mode for dehumidifying and optionally cooling and post-heating the intake air of the passenger compartment. Figure 1a The first system 1-1 of the third 3 / 2-way valve 29. The first port 29a of the third 3 / 2-way valve 29 is connected to the second port 29b so that the refrigerant flowing out of the compressor 3 at a high pressure level is directed to the second refrigerant / coolant heat exchanger 28 operating as a condenser / gas cooler. When flowing through the second refrigerant / coolant heat exchanger 28, the refrigerant is at least deheated and partially liquefied or cooled. Heat is transferred from the refrigerant to the coolant circulating in the coolant circuit. The heated coolant can be directed through heat exchangers 51, 52 for heating the intake air of the rear section of the passenger compartment.

[0112] The refrigerant then flows through the return device 31 and the first refrigerant / air heat exchanger 4 arranged in the first air flow passage 60 of the air conditioner. When flowing through the first refrigerant / air heat exchanger 4, the refrigerant is completely liquefied and supercooled or cooled. Heat is transferred from the refrigerant to the intake air for the front section of the passenger compartment. In doing so, the intake air, which was previously at least dehumidified, is heated.

[0113] After flowing out of the first refrigerant / air heat exchanger 4, the refrigerant is divided into a first partial mass flow and a second partial mass flow in the region of the second 3 / 2-way valve 27. The first partial mass flow is directed to the first branching point 11. The third partial mass flow of the refrigerant branches off from the first partial mass flow at the first branching point 11.

[0114] The first partial mass flow is directed to the second refrigerant / air heat exchanger 5 operating as a condenser / gas cooler through the first expansion member 6. When flowing through the first expansion member 6, the first partial mass flow of the refrigerant is relaxed to a medium pressure level or a low pressure level as required. When flowing through the second refrigerant / air heat exchanger 5, the refrigerant is at least partially evaporated. Heat is transferred from the ambient air to the refrigerant. The first partial mass flow of the refrigerant is then directed to the second expansion member 8. When flowing through the second expansion member 8, the first partial mass flow of the refrigerant relaxes from the medium pressure level to the low pressure level, or the first partial mass flow of the refrigerant flows through the second expansion member 8 at the same low pressure level while the second expansion member 8 is fully opened. The first partial mass flow of the refrigerant is then directed to the third refrigerant / air heat exchanger 7 operating as an evaporator.

[0115] A first partial mass flow of the refrigerant is evaporated and optionally superheated when flowing through the third refrigerant / air heat exchanger 7. Heat is transferred from the intake air of the passenger compartment, which is guided through the first air flow channel 60, to the refrigerant circulating in the refrigerant circuit 21. The intake air is dehumidified and optionally cooled, and then heated when flowing through the first refrigerant / air heat exchanger 4 and flows out into the front section of the passenger compartment.

[0116] When flowing through the third expansion member 10, the third partial mass flow of the refrigerant is relaxed to a low pressure level and is then directed to the first refrigerant / coolant heat exchanger 9. The first 3 / 2-way valve 13 is completely closed. When flowing through the first refrigerant / coolant heat exchanger 9, the refrigerant is evaporated and optionally superheated. Heat is transferred from the coolant circulating in the coolant circuit to the refrigerant circulating in the refrigerant circuit 21. The coolant can be used for active cooling of a battery of a motor vehicle or for receiving waste heat from components of an electric drive train.

[0117] The first partial mass flow and the third partial mass flow of the refrigerant mix with one another at the first opening point 12 and are introduced into the accumulator 17 .

[0118] The second partial mass flow of the subcooled refrigerant at a high pressure level branched in the region of the second 3 / 2-way valve 27 is guided from the first port 27a operated as an inlet to the second port 27b formed as an outlet of the second 3 / 2-way valve 27 without any pressure change. Then, the fourth partial mass flow of the refrigerant branches from the second partial mass flow at the third branching point 24. The second partial mass flow of the refrigerant flowing through the first flow path 22 is relaxed to a low pressure level when flowing through the fourth expansion member 19 and is guided to the fourth refrigerant / air heat exchanger 18, while the fourth partial mass flow of the refrigerant flowing through the second flow path 23 is relaxed to a low pressure level when flowing through the fifth expansion member 21 and is guided to the fifth refrigerant / air heat exchanger 20. The second partial mass flow and the fourth partial mass flow of the refrigerant are guided in parallel through the flow paths 22, 23. The second partial mass flow of the refrigerant through the fourth refrigerant / air heat exchanger 18 operated as evaporator and the fourth partial mass flow of the refrigerant through the fifth refrigerant / air heat exchanger 20 operated as evaporator are correspondingly adjusted by means of the fourth expansion member 19 and the fifth expansion member 21 .

[0119] When flowing through the fourth refrigerant / air heat exchanger 18 and the fifth refrigerant / air heat exchanger 20, the refrigerant is evaporated and optionally superheated, respectively. Heat is transferred from the intake air of the passenger compartment guided through the second air flow passage 61 and the third air flow passage 62, respectively, to the refrigerant circulating in the refrigerant circuit 2-1. In doing so, the intake air is dehumidified and optionally cooled, respectively, and is heated when flowing through the second heat exchanger 51 and the third heat exchanger 52 and then flows out into the rear section of the passenger compartment. The second partial mass flow and the fourth partial mass flow of the refrigerant are mixed with each other at the fourth opening point 25 and are guided to the fifth opening point 26-1 as the second partial mass flow. At the fifth opening point 26-1, the first partial mass flow is mixed with the second partial mass flow, and then the mixed first partial mass flow and the second partial mass flow are guided to the first opening point 12 as the first partial mass flow, and are mixed with the third partial mass flow at the first opening point 12, and flow into the accumulator 17. The evaporator 3 draws in refrigerant from the accumulator 17 .

[0120] exist Figure 5 middle, Figure 1aThe first system 1-1 is shown during operation of the refrigerant circuit 2-1 in a heating mode. The first port 29a of the third 3 / 2-way valve 29 is connected to the second port 29b so that the refrigerant flowing out of the compressor 3 at a high pressure level is directed to the second refrigerant / coolant heat exchanger 28 operating as a condenser / gas cooler. When flowing through the second refrigerant / coolant heat exchanger 28, the refrigerant is at least deheated and partially liquefied or cooled. Heat is transferred from the refrigerant to the coolant circulating in the coolant circuit. The heated coolant can be directed through heat exchangers 51, 52 for heating the incoming air of the rear section of the passenger compartment.

[0121] The refrigerant then flows through the return device 31 and the first refrigerant / air heat exchanger 4 arranged in the first air flow passage 60 of the air conditioner. The refrigerant is completely liquefied and optionally supercooled or cooled when flowing through the first refrigerant / air heat exchanger 4. Heat is transferred from the refrigerant to the intake air for the front section of the passenger compartment, which is thus heated.

[0122] After flowing out of the first refrigerant / air heat exchanger 4, the refrigerant is conducted to a first branching point 11. At the first branching point 11, the mass flow of the refrigerant is divided into a first partial mass flow and a second partial mass flow.

[0123] The first partial mass flow is directed to the second refrigerant / air heat exchanger 5 operating as a condenser / gas cooler through the first expansion member 6. When flowing through the first expansion member 6, the first partial mass flow of the refrigerant is relaxed to a low pressure level. When flowing through the second refrigerant / air heat exchanger 5, the refrigerant is evaporated and optionally superheated. Heat is transferred from the ambient air to the refrigerant. Then, the first partial mass flow of the refrigerant is directed through the second branch point 14 and through the first 3 / 2-way valve 13 from the first port 13a to the second port 13b without any pressure change.

[0124] When flowing through the third expansion member 10, the second partial mass flow of the refrigerant is relaxed to a low pressure level and is then directed to the first refrigerant / coolant heat exchanger 9. When flowing through the first refrigerant / coolant heat exchanger 9, the refrigerant is evaporated and optionally superheated. Heat is transferred from the coolant circulating in the coolant circuit to the refrigerant circulating in the refrigerant circuit 21. The coolant can be used for active cooling of a battery of a motor vehicle or for receiving waste heat from components of an electric drive train.

[0125] The first partial mass flow and the second partial mass flow of the refrigerant mix with one another at the first opening point 12 and are introduced into the accumulator 17 .

[0126] No refrigerant flows through the second 3 / 2-way valve 27. The second expansion member 8 and the fourth expansion member 19 and the fifth expansion member 21 are closed. The third refrigerant / air heat exchanger 7 and the fourth refrigerant / air heat exchanger 18 and the fifth refrigerant / air heat exchanger 20, which can be operated as evaporators, are not filled with refrigerant. The corresponding liquid refrigerant can be stored in a refrigerant line extending from the closed second 3 / 2-way valve 27, in particular from the second port 27b of the second 3 / 2-way valve 27 to the third branch point 24 and from the third branch point 24 to the fourth expansion member 19 and the fifth expansion member 21, so as to make the heat pump operation more energy-efficient. The refrigerant line is used as a refrigerant intermediate storage. Therefore, the life of the compressor 3 can be maximized, and the internal volume of the accumulator 17 can be minimized.

Claims

1. A system (1-1, 1-2) for air conditioning the air of a passenger compartment of a motor vehicle, the system (1-1, 1-2) having a refrigerant circuit (2-1, 2-2), the refrigerant circuit (2-1, 2-2) having: - compressor (3); - a first refrigerant / air heat exchanger (4) operable as a condenser / gas cooler for heating the intake air of the passenger compartment, a refrigerant path having a second refrigerant / air heat exchanger (5) operable as a condenser / gas cooler or evaporator for heat exchange with ambient air and having an upstream first expansion member (6) and a third refrigerant / air heat exchanger (7) operable as an evaporator for conditioning the intake air of the passenger compartment and having an upstream second expansion member (8), and a refrigerant circuit having a refrigerant / coolant heat exchanger (9) operable as an evaporator for exchanging heat between a coolant and a refrigerant for controlling the temperature of at least one component of a drive train of the motor vehicle and having an upstream third expansion member (10), in, The refrigerant path having the second refrigerant / air heat exchanger (5) and the third refrigerant / air heat exchanger (7) and the refrigerant path having the refrigerant / coolant heat exchanger (9) capable of operating as an evaporator extend from a branch point (11) to an opening point (12) respectively, and are formed so that the refrigerant paths can be charged with refrigerant independently and in parallel with each other, characterized in that the refrigerant circuit (2-1, 2-2) has a connection point with a first port (27a), a second port (27b) and a third port (27c), wherein the first port (27a) is arranged between the first expansion member (6) of the first refrigerant / air heat exchanger (4) and the second refrigerant / air heat exchanger (5), and the third port (27c) is arranged between the second refrigerant / air heat exchanger (5) and the second expansion member (8) of the third refrigerant / air heat exchanger (7), and a connection point (26a) is formed so that the refrigerant paths can be charged with refrigerant independently and in parallel with each other. 1, 26-2) extends with the following refrigerant path: in the refrigerant path, at least one refrigerant / air heat exchanger (18, 20) is arranged, and the at least one refrigerant / air heat exchanger (18, 20) can be operated as an evaporator for conditioning the intake air of the passenger compartment and has an upstream expansion member (19, 21), wherein the opening point (26-1, 26-2) is arranged upstream of the compressor (3) along the flow direction of the refrigerant.

2. The system (1-1, 1-2) according to claim 1, characterized in that: The refrigerant path extending from the third port (27c) of the connection point to the opening point (26-1, 26-2) has a first flow path (22) and a second flow path (23), the first flow path (22) and the second flow path (23) respectively extending from the branch point (14) to the opening point (25), and are formed so that the first flow path (22) and the second flow path (23) can be filled with refrigerant independently and in parallel with each other, wherein the first flow path (22) has a fourth refrigerant / air heat exchanger (18) with an upstream fourth expansion member (19) capable of operating as an evaporator, and the second flow path (23) has a fifth refrigerant / air heat exchanger (20) with an upstream fifth expansion member (21) capable of operating as an evaporator.

3. The system (1-1, 1-2) according to claim 1 or 2, characterized in that: The branch point (11) of the refrigerant path having the second refrigerant / air heat exchanger (5) and the third refrigerant / air heat exchanger (7) and the refrigerant path having the refrigerant / coolant heat exchanger (9) capable of operating as an evaporator are arranged between the first refrigerant / air heat exchanger (4) and the first expansion member (6) of the second refrigerant / air heat exchanger (5).

4. The system (1-1, 1-2) according to any one of claims 1 to 3, characterized in that The opening point (12) of the refrigerant path having the second refrigerant / air heat exchanger (5) and the third refrigerant / air heat exchanger (7) and the refrigerant path having the refrigerant / coolant heat exchanger (9) operable as an evaporator are arranged upstream of the compressor (3) in the flow direction of the refrigerant.

5. The system (1-1, 1-2) according to any one of claims 1 to 4, characterized in that The connection point is formed as a 3 / 2-way valve (27) having the first port (27a) as an inlet, the second port (27b) as an outlet, and the third port (27c) as an inlet and an outlet.

6. The system (1-1, 1-2) according to any one of claims 1 to 5, characterized in that The refrigerant circuit (2-1, 2-2) has an accumulator (17) which is arranged upstream of the compressor (3) along the flow direction of the refrigerant.

7. The system (1-1) according to claim 6, characterized in that The opening point (26-1) of the refrigerant path extending from the third port (27c) of the connection point is arranged between the third refrigerant / air heat exchanger (7) and the compressor (3), in particular, upstream of the accumulator (17) in the flow direction of the refrigerant.

8. The system (1-2) according to claim 6, characterized in that The opening point (26-2) of the refrigerant path extending from the third port (27c) of the connection point is arranged between the accumulator (17) and the compressor (3).

9. The system (1-1, 1-2) according to any one of claims 1 to 8, characterized in that The refrigerant circuit (2-1, 2-2) has a connection point formed as a 3 / 2-way valve (13), the 3 / 2-way valve (13) has an expansion function and has a first port (13a), a second port (13b) and a third port (13c), wherein the first port (13a) is formed as an inlet, and the second port (13b) and the third port (13c) are respectively formed as outlets, and the expansion function is formed between the first port (13a) and the third port (13c).

10. The system (1-1, 1-2) according to claim 9, characterized in that: The first port (13a) of the 3 / 2-way valve (13) is connected to a branch point (14) arranged between the second refrigerant / air heat exchanger (5) and the second expansion member (8) of the third refrigerant / air heat exchanger (7), the second port (13b) of the 3 / 2-way valve (13) is connected to an opening point (15) arranged between the third refrigerant / air heat exchanger (7) and the compressor (3), and the third port (13c) of the 3 / 2-way valve (13) is connected to an opening point (16) arranged between the third expansion member (10) and the refrigerant / coolant heat exchanger (9) which can be operated as an evaporator.

11. System (1-1, 1-2) according to one of claims 2 to 10, characterized in that An air conditioner is formed having at least two air flow passages (60, 61, 62), wherein - the third refrigerant / air heat exchanger (7) operable as an evaporator for conditioning the intake air of the passenger compartment and the first refrigerant / air heat exchanger (4) operable as a condenser / gas cooler for heating the intake air of the passenger compartment are arranged one after another in a first air flow channel (60) along the flow direction of the intake air, the first air flow channel (60) opening into the passenger compartment in a front section of the passenger compartment, and - The fourth refrigerant / air heat exchanger (18) operable as an evaporator for conditioning the intake air of the passenger compartment is arranged in a second air flow channel (61) which opens into the passenger compartment in a rear section of the passenger compartment.

12. The system (1-1, 1-2) according to claim 11, characterized in that The fifth refrigerant / air heat exchanger (20) operable as an evaporator for conditioning the intake air of the passenger compartment is arranged in a third air flow passage (62) which opens into the passenger compartment in a rear section of the passenger compartment.

13. The system (1-1, 1-2) according to any one of claims 11 or 12, characterized in that Respective heat exchangers (50, 51, 52) formed as refrigerant / air heat exchangers or electric PTC heaters for heating the intake air are arranged downstream of the refrigerant / air heat exchangers (7, 18, 20) in the flow direction of the intake air within corresponding air flow channels (60, 61, 62).

14. The system (1-1, 1-2) according to any one of claims 1 to 13, characterized in that The refrigerant circuit (2-1, 2-2) has a refrigerant / coolant heat exchanger (28) capable of operating as a condenser / gas cooler and a branch point formed as a 3 / 2-way valve (29) having a first port (29a), a second port (29b) and a third port (29c), wherein the first port (29a) is formed as an inlet and the second port (29b) and the third port (29c) are respectively formed as outlets.

15. The system (1-1, 1-2) according to claim 14, characterized in that The first port (29a) of the 3 / 2-way valve (29) is connected to the outlet of the compressor (3), the second port (29b) of the 3 / 2-way valve (29) is connected to the refrigerant / air heat exchanger (28) which can be operated as a condenser / gas cooler, and the third port (29c) of the 3 / 2-way valve (29) is connected to an opening point (30) arranged upstream of the first refrigerant / air heat exchanger (4) along the flow direction of the refrigerant.

16. The system (1-1, 1-2) according to claim 14 or 15, characterized in that The refrigerant / coolant heat exchanger (28) operable as a condenser / gas cooler is arranged in a flow path extending between the second port (29b) of the 3 / 2-way valve (29) to the opening point (30) arranged upstream of the first refrigerant / air heat exchanger (4).

17. A method for operating a system (1-1, 1-2) for air conditioning the air of a passenger compartment of a motor vehicle according to any one of claims 1 to 16 in a refrigeration device mode for conditioning, in particular cooling and / or dehumidifying, the intake air of the passenger compartment, the method comprising the following steps: - directing the refrigerant circulating in the refrigerant circuit (2-1, 2-2) and flowing out of the compressor (3) at a high pressure level through the first expansion member (6) to the second refrigerant / air heat exchanger (5) operating as a condenser / gas cooler, and transferring heat from the refrigerant at a high pressure level to the ambient air, wherein The first expansion member (6) is fully opened, and the refrigerant is fully liquefied and subcooled or cooled while flowing through the second refrigerant / air heat exchanger (5), - directing the refrigerant flowing out of the second refrigerant / air heat exchanger (5) to the connection point formed as a 3 / 2-way valve (27), and - dividing the refrigerant into a partial mass flow through a third refrigerant / air heat exchanger (7) operating as an evaporator with an upstream second expansion member (8) and a partial mass flow through the refrigerant path extending from the third port (27c) of the 3 / 2-way valve (27) to the opening point (26-1, 26-2), the refrigerant path having at least one refrigerant / air heat exchanger (18, 20) operating as an evaporator with an upstream expansion member (19, 21), - relaxing the partial mass flow to a low pressure level when it flows through the expansion member (8, 19, 21) and directing the partial mass flow to the refrigerant / air heat exchanger (7, 18, 20) operating as an evaporator, - evaporating and optionally superheating the partial mass flow when it flows through the refrigerant / air heat exchanger (7, 18, 20) operating as an evaporator, wherein corresponding heat is transferred to the refrigerant from the intake air of the passenger compartment guided through air flow channels (60, 61, 62), wherein the intake air is cooled and / or dehumidified and flows out of the air flow channels (60, 61, 62) into a front section of the passenger compartment and a rear section of the passenger compartment, respectively, and - mixing the partial mass flow of the refrigerant upstream of the compressor (3) in the flow direction of the refrigerant and sucking the refrigerant through the compressor (3).

18. The method according to claim 17, characterized in that The partial mass flow of the refrigerant guided through the refrigerant path extending from the third port (27c) of the 3 / 2-way valve (27) to the opening point (26-1, 26-2) is divided into a partial mass flow through a first flow path (22) and a partial mass flow through a second flow path (23), wherein the partial mass flow flowing through the first flow path (22) and the partial mass flow flowing through the second flow path (23) are relaxed to the desired values ​​when flowing through the expansion members (19, 21), respectively. said low pressure level and is evaporated and optionally superheated while flowing through the refrigerant / air heat exchanger (18, 20), wherein corresponding heat is transferred to the refrigerant from the intake air of the passenger compartment which is guided through one of the air flow channels (61, 62), wherein the intake air is respectively cooled and / or dehumidified and flows out of the air flow channels (61, 62) into the rear section of the passenger compartment, and wherein partial mass flows of the vaporous and optionally superheated refrigerant mix with one another.

19. The method according to claim 17 or 18, characterized in that The refrigerant flowing out of the second refrigerant / air heat exchanger (5) is divided into a partial mass flow leading to the connection point formed as a 3 / 2-way valve (27) and a partial mass flow leading to a 3 / 2-way valve (13) with an expansion function, wherein the partial mass flow guided to the 3 / 2-way valve (13) with an expansion function is relaxed to the low pressure level when flowing through the 3 / 2-way valve (13) and is evaporated and optionally superheated when flowing through the refrigerant / coolant heat exchanger (9) operating as an evaporator, wherein heat from the coolant circulating in the coolant circuit is transferred to the refrigerant circulating in the refrigerant circuit (2-1, 2-2), and the partial mass flows of the refrigerants are mixed with each other before being sucked into the compressor (3).

20. The method according to any one of claims 17 to 19, characterized in that The refrigerant flowing out of the compressor (3) at a high pressure level is directed to a refrigerant / coolant heat exchanger (28) operating as a condenser / gas cooler, wherein the refrigerant is at least deheated and partially liquefied or cooled while flowing through the refrigerant / coolant heat exchanger (28), and heat is transferred from the refrigerant to the coolant circulating in a coolant circuit.

21. A method for operating a system (1-1, 1-2) for air conditioning the air of a passenger compartment of a motor vehicle according to any one of claims 1 to 16 in an afterheating mode for conditioning, in particular dehumidifying and optionally cooling and afterheating the intake air of the passenger compartment, the method comprising the following steps: - directing the refrigerant circulating in the refrigerant circuit (2-1, 2-2) and flowing out of the compressor (3) at a high pressure level to a refrigerant / coolant heat exchanger (28) operating as a condenser / gas cooler, and transferring heat from the refrigerant to the coolant circulating in the coolant circuit, wherein The refrigerant is at least deheated and partially liquefied or cooled while flowing through the refrigerant / coolant heat exchanger (28), wherein the heated coolant is conducted through a heat exchanger (51, 52) filled with the intake air for heating the previously dehumidified and optionally cooled intake air of the rear section of the passenger compartment, - directing the refrigerant flowing out of the refrigerant / coolant heat exchanger (28) operating as a condenser / gas cooler to the first refrigerant / air heat exchanger (4) and transferring heat from the refrigerant at the high pressure level to the intake air for the front section of the passenger compartment, wherein the refrigerant is completely liquefied and supercooled or cooled while flowing through the first refrigerant / air heat exchanger (4), and the previously dehumidified and optionally cooled intake air is heated, - directing the refrigerant flowing out of the first refrigerant / air heat exchanger (4) to the connection point formed as a 3 / 2-way valve (27), and - dividing the refrigerant into a partial mass flow through the second refrigerant / air heat exchanger (5) operating as an evaporator with an upstream first expansion member (6) and a partial mass flow through the refrigerant path extending from the third port (27c) of the 3 / 2-way valve (27) to the opening point (26-1, 26-2), the refrigerant path having at least one refrigerant / air heat exchanger (18, 20) operating as an evaporator with an upstream expansion member (19, 21), - the partial mass flow of the refrigerant to be directed to the second refrigerant / air heat exchanger (5) is relaxed to an intermediate pressure level or a low pressure level when flowing through the first expansion member (6), and the partial mass flow is directed through the second refrigerant / air heat exchanger (5) operating as an evaporator, wherein the refrigerant at least partially evaporates and heat is transferred from the ambient air to the refrigerant, and the partial mass flow of the refrigerant flowing out of the second refrigerant / air heat exchanger (5) is directed to the third refrigerant / air heat exchanger (7) operating as an evaporator with an upstream second expansion member (8), and the partial mass flow is relaxed to a low pressure level when flowing through the second expansion member (8), and the partial mass flow is directed to the third refrigerant / air heat exchanger (7) operating as an evaporator, - the partial mass flow of the refrigerant to be guided through the refrigerant path extending from the third port (27c) of the 3 / 2-way valve (27) to the opening point (26-1, 26-2), wherein the refrigerant path has the at least one refrigerant / air heat exchanger (18, 20) operating as an evaporator with the expansion member (19, 21), is relaxed to the low pressure level when flowing through the upstream expansion member (19, 21), and the partial mass flow is guided to the refrigerant / air heat exchanger (18, 20) operating as an evaporator. - evaporating and optionally superheating the partial mass flow of the refrigerant when it flows through the refrigerant / air heat exchanger (7, 18, 20) operating as an evaporator, wherein corresponding heat is transferred to the refrigerant from the intake air of the passenger compartment guided through the air flow channel (60, 61, 62), wherein the intake air is cooled and / or dehumidified, wherein the intake air flowing through the first refrigerant / air heat exchanger (4) is heated and flows out into the front section of the passenger compartment, and the intake air flowing through the heat exchanger (51, 52) is heated and flows out into the rear section of the passenger compartment, and - The partial mass flows of the refrigerant are mixed and the refrigerant is sucked in through the compressor (3).

22. The method according to claim 21, characterized in that The partial mass flow of the refrigerant guided through the refrigerant path extending from the third port (27c) of the 3 / 2-way valve (27) to the opening point (26-1, 26-2) is divided into a partial mass flow through a first flow path (22) and a partial mass flow through a second flow path (23), wherein the partial mass flow flowing through the first flow path (22) and the partial mass flow flowing through the second flow path (23) are relaxed to the low pressure level when flowing through the expansion members (19, 21), respectively, and are separated into a partial mass flow flowing through the first flow path (22) and a partial mass flow flowing through the second flow path (23) when flowing through the expansion members (19, 21), respectively. is evaporated and optionally superheated when passing through the refrigerant / air heat exchanger (18, 20), wherein corresponding heat is transferred to the refrigerant from the intake air of the passenger compartment which is guided through one of the air flow channels (61, 62), wherein the intake air is respectively cooled and / or dehumidified, is heated when flowing through the heat exchanger (51, 52) and flows out of the air flow channels (61, 62) into the rear section of the passenger compartment, and wherein partial mass flows of the vaporous and optionally superheated refrigerant mix with one another.

23. The method according to claim 21 or 22, characterized in that The partial mass flow of the refrigerant directed to the second refrigerant / air heat exchanger (5) operating as an evaporator with an upstream first expansion member (6) is divided into a partial mass flow to the first expansion member (6) and a partial mass flow to the refrigerant / coolant heat exchanger (9) operating as an evaporator with an upstream third expansion member (10), wherein the partial mass flow directed to the refrigerant / coolant heat exchanger (9) operating as an evaporator is relaxed to a low pressure level when flowing through the third expansion member (10) and is evaporated and optionally superheated when flowing through the refrigerant / coolant heat exchanger (9), wherein heat is transferred from the coolant circulating in the coolant circuit to the refrigerant circulating in the refrigerant circuit (2-1, 2-2), and the partial mass flows of the refrigerants are mixed with each other before being sucked into the compressor (3).

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