DE102016112089A1 - Air conditioning system for a motor vehicle - Google Patents

Abstract

The invention relates to an air conditioning system (1, 1 ', 1' ', 1' '', 1 '' '', 1 '' '' ') for a motor vehicle having at least one first refrigerant circuit (2, 2' ', 2'). '' '') and a second refrigerant circuit (7, 7 '', 7 '' '' ') for the independent conditioning of air mass flows to be supplied to a passenger compartment. The refrigerant circuits (2, 2 '', 2 '' '', 7, 7 '', 7 '' '' ') each have a compressor (3, 8), one operated as a condenser / gas cooler (4, 9) Heat exchanger, at least one expansion element (5, 10, 11, 11 '') and at least one as an evaporator (6, 12, 13, 13 a, 13 '') operated heat exchanger. The air conditioning system (1, 1 ', 1' ', 1' '', 1 '' '', 1 '' '' ') is also provided with at least a first coolant circuit (14, 14' '' ') and a second coolant circuit (20) formed. The condenser / gas cooler (4) of the first refrigerant circuit (2, 2 '', 2 '' '' ') is as a refrigerant-air heat exchanger (4) for transmitting heat to the ambient air and the condenser / gas cooler (9) of second refrigerant circuit (7, 7 '', 7 '' '' ') is designed as a refrigerant-refrigerant heat exchanger (9) for transmitting heat to the first coolant circuit (14, 14' '' '), wherein the first coolant circuit ( 14, 14 "") is configured as a low-temperature coolant circuit.

Description

The invention relates to an air conditioning system, in particular a thermal management system, for a motor vehicle with high refrigeration demand with at least a first and a second refrigerant circuit for the independent conditioning of a passenger compartment to be supplied air mass flows. The refrigerant circuits each have a compressor, a heat exchanger operated as a condenser / gas cooler, at least one expansion element and at least one heat exchanger operated as an evaporator. The air conditioning system is also formed with at least a first and a second coolant circuit.

From the prior art known passenger vehicles with a large-volume passenger compartment, such as sports and commercial vehicles or SUVs, also referred to as SUV, vehicles with elevated body, high-roof or minibuses, also referred to as VAN, or luxury vehicles are with Air conditioning systems and refrigerant circuits are formed with at least two evaporators to separately air-condition different areas of the passenger compartment. In this case, the passenger compartment is divided in particular into a front and a rear area. The terms front area, also referred to as front area, and rear area, also referred to as the rear area, relate to the direction of travel of the motor vehicle. A first air mass flow is conditioned when flowing over a first evaporator, the so-called front evaporator, and directed into the front region of the passenger compartment in order to generate a comfortable climate for both the driver and the front passenger. A second air mass flow is conditioned when flowing over a second evaporator, the so-called rear evaporator, and directed into the rear region of the passenger compartment in order to generate a comfortable climate for the occupants of the second and possibly the third row of seats within the passenger compartment.

The front evaporator and the rear evaporator are arranged in separate air conditioning units. In this case, each air conditioner independently provide a desired air flow with a required air temperature and a predetermined air flow direction. Electric vehicles, referred to as EV for short, or hybrid vehicles, abbreviated as HEV, due to the training with additional components, such as a high-voltage battery, an internal charger, a transformer, an inverter and the electric motor, usually have a higher refrigeration demand than motor vehicles with a pure internal combustion engine Drive up. In particular, in order to comply with the permitted temperature limits of the high-voltage battery, which are usually between 20 ° C and 35 ° C, either an additional refrigerant-refrigerant heat exchanger, also referred to as a chiller, or provided as a battery cooler direct refrigerant-cooled heat exchanger is provided. In addition, conventional electric hybrid electric vehicles have a low-temperature refrigerant circuit in which the refrigerant circulating to dissipate the heat emitted from the driving components is passed through an air-cooled low-temperature radiator. When flowing through the low-temperature radiator, at least a portion of the heat is transferred from the coolant to the ambient air. In this case, the heat can be dissipated by components which are operated at higher temperatures than the ambient temperature, such as the electric drive motor or the inverter, which allow operation at temperatures of up to 90 ° C. Low-temperature coolant circuits are increasingly being used in models of motor vehicles which are driven exclusively by internal combustion engines to cool the charge air or the transmission oil via a heat exchanger designed as an indirect intercooler or via a heat exchanger designed as a transmission oil cooler. A motor vehicle with an electric hybrid engine hybrid drive and a large passenger compartment thus has a comparatively high demand for refrigeration. A known from the prior art air conditioning system with a refrigerant circuit with a single compressor is not able to provide the required for the cooling of the passenger compartment and the electrical components mass flow of the refrigerant.

For the provision of comparatively high cooling capacities different air conditioning systems are known. On the one hand, in a conventional refrigerant circuit at least two compressors are operated in parallel, so that the mass flow of the refrigerant is doubled or multiplied. On the other hand, at least two refrigerant circuits are formed independently of each other, each additional refrigerant circuit having additional components.

In the US 7,228,707 B2 and in the US 2013/0145781 A1 In each case, a refrigerant circuit with parallel compressors are described. The compressors, which are connected in parallel, compress the refrigerant into a common pressure line, which conducts the refrigerant to a heat exchanger operated as a condenser. The from the US 7,228,707 B2 known refrigerant circuit in Economizerschaltung also has a variety of operated as an evaporator heat exchanger, which for Conditioning different environments serve. Each evaporator is connected to a compressor. The US 2013/0145781 A1 discloses a refrigerant circuit with two compressors, wherein the first compressor speed-controlled and the second compressor are designed to operate at a fixed speed.

In the refrigerant circuits known from the prior art, the individual components, such as the operated as a condenser / gas cooler heat exchanger, the refrigerant pipes as connecting lines between the components, optionally an internal heat exchanger and the valves, according to the high maximum mass flow of the refrigerant must be very large , In motor vehicles with a hybrid electric drive and in motor vehicles with a pure internal combustion engine drive, an additional coolant-air heat exchanger, in particular a low-temperature radiator, is already integrated in the coolant circuit, so that there is no installation space for a larger-sized condenser / gas cooler in the front region of the motor vehicle. In addition, large-dimensioned or for many operating points of the system oversized refrigerant pipes are to be laid. Although individual flow paths and thus evaporators are shut off independently of each other, the evaporators are only mutually operable pressure-dependent. With simultaneous operation, the evaporators, even by the use of costly electrical expansion valves, very costly to match each other.

In air conditioning systems with refrigerant circuits to be operated independently of each other, each with separately formed components, therefore, at least one further condenser / gas cooler is always required. Since in motor vehicles with a hybrid electric drive or a pure internal combustion engine drive in the coolant circuit already an additional coolant-air heat exchanger, in particular a low-temperature radiator is integrated, the free space in the front area of the motor vehicle is limited such that an integration of another capacitor / Gas cooler is almost impossible.

In known from the prior art different air conditioning systems with a refrigerant circuit with parallel operated compressors or with different refrigerant circuits are also the rear evaporator and possibly further evaporators in each case connected by refrigerant pipes to the front of the motor vehicle arranged condenser / gas cooler. The refrigerant pipes are to be laid through the entire motor vehicle and take up valuable space. The refrigerant lines are designed for high pressures and require special fasteners, which is very expensive. Furthermore, refrigerant pipes with a long length also cause high pressure losses in the refrigerant circuit, which leads to a reduced cooling capacity or a higher compressor capacity.

The object of the invention is to provide an air conditioning system with sufficient cooling capacity for motor vehicles with a large refrigeration demand, for example for motor vehicles with a combined electric and internal combustion engine drive, which also have a large-capacity passenger compartment. The manufacturing, maintenance and operating costs and the required installation space should be minimal and the refrigerant circuit should be formed from dimensioned for conventional mass flow components. The air conditioning system should be operable with maximum efficiency. In doing so, distances as short as possible should be overcome with the refrigerant lines in order to avoid high pressure losses within the refrigerant circuit.

The object is achieved by the subject matter with the features of the independent patent claim. Further developments are specified in the dependent claims.

The object is achieved by an inventive air conditioning system for a motor vehicle having at least a first refrigerant circuit as a primary refrigerant circuit for conditioning the supply air for a front portion of a passenger compartment and a second refrigerant circuit as a secondary refrigerant circuit for conditioning the supply air for a rear portion of the passenger compartment. The primary refrigerant circuit and the secondary refrigerant circuit are used for independent conditioning of the passenger compartment to be supplied air mass flows and each have a compressor for compressing the refrigerant, operated as a condenser / gas cooler heat exchanger for cooling and / or liquefaction of the compressed refrigerant, at least one expansion element and at least one operated as an evaporator Heat exchanger for evaporation of the refrigerant. The air conditioning system is also formed with at least a first coolant circuit and a second coolant circuit.

According to the concept of the invention, the heat exchangers of the first refrigerant circuit operated as a condenser / gas cooler are used as refrigerant-air heat exchangers for transmitting heat to the ambient air and the heat exchanger of the second refrigerant circuit operated as a condenser / gas cooler as the refrigerant-refrigerant heat exchanger for transmitting heat to the formed first coolant circuit. In this case, the first coolant circuit is configured as a low-temperature coolant circuit.

If the liquefaction of the refrigerant occurs in subcritical operation, such as with the refrigerant R134a or in certain ambient conditions with carbon dioxide, the heat exchangers are referred to as a condenser. Part of the heat transfer takes place at a constant temperature. In supercritical operation or supercritical heat in the heat exchanger, the temperature of the refrigerant steadily decreases. In this case, the heat exchanger is also referred to as a gas cooler. Supercritical operation may occur under certain environmental conditions or operations of the refrigerant cycle with, for example, the refrigerant carbon dioxide.

According to a preferred embodiment of the invention, the second coolant circuit for cooling a drive motor is designed as a high-temperature coolant circuit and has at least one heating heat exchanger for conditioning at least one air mass flow to be supplied to the passenger compartment and a coolant-air heat exchanger for transmitting heat to the ambient air. The heating heat exchanger and the coolant-air heat exchanger are preferably independently acted upon with coolant. The drive motor is advantageously designed as an internal combustion engine. The first coolant circuit is preferably operated at a lower temperature level than the second coolant circuit, so that the first coolant circuit is also referred to as a low-temperature coolant circuit and the second coolant circuit as a high-temperature coolant circuit.

According to a development of the invention, the second coolant circuit has a first flow path with a first heat exchanger for transmitting heat to the supply air for a front region of the passenger compartment and a second flow path with a second heat exchanger for transmitting heat to the supply air for a rear region of the passenger compartment on. In this case, the flow paths each extend from a branching point to an outlet point and can be acted upon independently with coolant.

The branch point of the first flow path is advantageously designed as a three-way valve, which is also configured to change a flow cross-section of a flow path with the coolant-air heat exchanger for transmitting heat from the coolant to the ambient air. The second flow path preferably has a shut-off valve. The three-way valve and the shut-off valve can be operated independently of each other. The different flow paths with the Heizwärmeübertragern and the coolant-air heat exchanger can be flowed through parallel to each other with coolant.

According to an advantageous embodiment of the invention, the first coolant circuit for receiving heat from the second refrigerant circuit with the refrigerant-refrigerant heat exchanger and for receiving heat from heat-generating components of the motor vehicle is formed with different flow paths and has a coolant-air heat exchanger for the transmission of Heat to the ambient air. The flow paths each extend from a branch point to an outlet point and can be acted upon independently with coolant. The branch point of the flow paths is advantageously designed as a three-way valve, which is configured to change the flow cross sections of the flow paths.

According to a first alternative embodiment of the invention, a third coolant circuit is provided with a heat exchanger for transmitting heat to the coolant and designed as an evaporator for a refrigerant refrigerant-coolant heat exchanger for transferring heat to the refrigerant. The heat exchanger for transmitting heat to the coolant is preferably configured for cooling an electrical component, for example a high-voltage battery of an electric drive train of the motor vehicle.

The refrigerant-refrigerant heat exchanger for transmitting heat to the refrigerant is advantageously formed as a component of the second refrigerant circuit or as a component of the first refrigerant circuit.

According to a second alternative embodiment of the invention, the air conditioning system is designed with a heat exchanger in combination with a designed as an evaporator for a refrigerant heat exchanger for the direct transfer of heat to the refrigerant. The evaporator is preferably designed as a component of the second refrigerant circuit or as a component of the first refrigerant circuit.

A further advantageous embodiment of the invention consists in that at least one refrigerant circuit has two flow paths, each with a heat exchanger operated as an evaporator and an expansion element disposed upstream in the flow direction of the refrigerant. The flow paths are parallel to each other arranged and acted upon individually or in parallel with each other with refrigerant as needed.

According to a development of the invention, at least one of the refrigerant circuits is formed with an internal heat exchanger for heat transfer between the refrigerant at high pressure and the refrigerant at low pressure.

According to a preferred embodiment of the invention, at least one third refrigerant circuit as a secondary refrigerant circuit with a compressor for compressing the refrigerant, a heat exchanger operated as a condenser / gas cooler for cooling and / or liquefying the compressed refrigerant, at least one expansion element and at least one operated as an evaporator heat exchanger for evaporation formed of the two-phase refrigerant. In this case, the condenser / gas cooler is configured as a refrigerant-refrigerant heat exchanger for transmitting heat to the first coolant circuit.

The first coolant circuit is advantageous for receiving heat from the second refrigerant circuit with a refrigerant-refrigerant heat exchanger, for receiving heat from heat-generating components of the motor vehicle and for receiving heat from the third refrigerant circuit with a refrigerant-refrigerant heat exchanger having different flow paths and has a refrigerant-air heat exchanger for transmitting heat to the ambient air. The flow paths each extend from a branch point to an outlet point and can be acted upon independently with coolant.

The branch points of the flow paths are preferably designed as three-way valves.

• – Bereitstellen eines im Vergleich zu bekannten Systemen höheren Massenstroms an Kältemittel und damit einer hohen Kälteleistung durch den Einsatz von mindestens zwei Kältemittelverdichtern,
• – durch die Entkopplung der Kältemittelkreisläufe und den Einsatz der mindestens zwei Verdichter ist die Kälteleistung des Gesamtsystems sehr gut regelbar,
• – mit der Aufteilung in einen Primärkältemittelkreislauf und Sekundärkältemittelkreislauf wird die Druckabhängigkeit der Verdampfer voneinander aufgehoben,
• – damit werden eine hohe Dynamik sowie eine hohe Flexibilität während des Betriebs gewährleistet,
• – sämtliche Komponenten des Primärkältemittelkreislaufs und des Sekundärkältemittelkreislaufs sind exakt auf den gewünschten Kältebedarf dimensionierbar, was zu kleineren und somit leichteren Komponenten führt,
• – Einsatz eines einzigen luftgekühlten Kältemittel-Luft-Wärmeübertragers als Kondensator/Gaskühler im Primärkältemittelkreislauf zur Enthitzung und/oder zur Kondensation des Kältemittels, wobei die Enthitzungswärme und die Kondensationswärme im Sekundärkältemittelkreislauf über einen kühlmittelgekühlten Kondensator/Gaskühler in den Niedertemperatur-Kühlmittelkreislauf übertragen wird, welche über den Niedertemperatur-Kühler an die Umgebungsluft abgegeben wird,
• – kurze Kältemittelleitungen, insbesondere im Sekundärkältemittelkreislauf, da sowohl der Verdichter als auch der kühlmittelgekühlte Kondensator/Gaskühler variabel und ortsunabhängig anordenbar sind, was auch den kältemittelseitigen Gesamtdruckverlust innerhalb des Kältemittelkreislaufs minimiert,
• – damit maximale Effizienz des Klimatisierungssystems beim Betrieb und minimaler Bauraum sowie
• – geringe Kosten bei der Herstellung und Wartung sowie während des Betriebs.

The air conditioning system according to the invention has in summary various advantages:

• Providing a higher mass flow of refrigerant compared to known systems and thus a high cooling capacity through the use of at least two refrigerant compressors,
• - By decoupling the refrigerant circuits and the use of at least two compressors, the cooling capacity of the entire system is very easy to control,
• With the division into a primary refrigerant circuit and secondary refrigerant circuit, the pressure dependence of the evaporators is canceled,
• - ensuring high dynamics and high flexibility during operation,
• - All components of the primary refrigerant circuit and the secondary refrigerant circuit can be dimensioned exactly to the desired refrigeration demand, resulting in smaller and thus lighter components,
• - Use of a single air-cooled refrigerant-air heat exchanger as a condenser / gas cooler in the primary refrigerant circuit for dehumidification and / or condensation of the refrigerant, wherein the Enthitzungswärme and the heat of condensation in the secondary refrigerant circuit is transmitted via a coolant-cooled condenser / gas cooler in the low-temperature refrigerant circuit, which the low-temperature cooler is released into the ambient air,
• Short refrigerant lines, in particular in the secondary refrigerant circuit, since both the compressor and the coolant-cooled condenser / gas cooler can be arranged variably and independently of location, which also minimizes the overall refrigerant-side pressure loss within the refrigerant circuit,
• - Thus maximum efficiency of the air conditioning system during operation and minimal space and
• - low production and maintenance costs as well as during operation.

The air conditioning system, in particular the refrigerant circuits, are independent of the refrigerant used and therefore also designed for R134a, R744, R1234yf or other refrigerants.

Further details, features and advantages of embodiments of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Each shows an air conditioning system of a motor vehicle having a first refrigerant circuit for conditioning the air for the front region of the passenger compartment and a second refrigerant circuit for conditioning the air for the rear region of the passenger compartment and a first coolant circuit for receiving heat from the second refrigerant circuit and a second Coolant circuit for cooling a drive motor and, if necessary, for heating the supply air for the passenger compartment:

1 with a third coolant circuit, which is thermally coupled to the second refrigerant circuit and has a heat exchanger for cooling a battery,

2 with a heat exchanger for cooling a battery, which is thermally coupled directly to the second refrigerant circuit,

3 with a third coolant circuit, which is thermally coupled to the first refrigerant circuit and has a heat exchanger for cooling a battery,

4 : to 2 without heat exchanger for cooling the battery,

5 : to 1 with internal heat exchangers in the refrigerant circuits and

6 : to 1 with a third refrigerant circuit, which is thermally coupled to the first coolant circuit.

Out 1 goes an air conditioning system 1 a motor vehicle with a first refrigerant circuit 2 for conditioning the supply air for the front area of the passenger compartment and a second refrigerant circuit 7 for conditioning the supply air to the rear of the passenger compartment. The air conditioning system 1 also has a first coolant circuit 14 for receiving heat from the second refrigerant circuit 7 , a second coolant circuit 20 for cooling a drive motor 32 and if necessary, for heating the supply air for the front and the rear of the passenger compartment and a third coolant circuit 33 on. The third coolant circuit 33 is via an operated as an evaporator refrigerant-refrigerant heat exchanger 13 , which is also referred to as a chiller, with the second refrigerant circuit 7 thermally coupled and with a heat exchanger 35 for cooling an electrical component, such as a high-voltage battery.

The first refrigerant circuit 2 , hereinafter also as a primary refrigerant circuit 2 denotes, has a compressor in the flow direction of the refrigerant 3 , one as a condenser / gas cooler 4 operated refrigerant-air heat exchanger 4 , an expansion organ 5 and operated as an evaporator refrigerant-air heat exchanger 6 on. That from the evaporator 6 escaping refrigerant is from the compressor 3 sucked. The refrigerant circuit 2 is closed. The evaporation of the refrigerant in the evaporator 6 generated cooling capacity is used for cooling a passenger compartment in the front area supplied air mass flow. The heat absorbed by the refrigerant is flowing through the arranged in the front region of the vehicle refrigerant-air heat exchanger 4 transferred as deheating heat or condensation heat to the ambient air.

The second refrigerant circuit 7 , in the following also as a secondary refrigerant circuit 7 denotes, has a compressor in the flow direction of the refrigerant 8th , one as a condenser / gas cooler 9 operated refrigerant-refrigerant heat exchanger 9 , an expansion organ 10 and operated as an evaporator refrigerant-air heat exchanger 12 on. That from the evaporator 12 escaping refrigerant is from the compressor 8th sucked. The refrigerant circuit 7 is closed. The evaporation of the refrigerant in the evaporator 12 generated cooling capacity is used for cooling an air mass flow supplied to the passenger compartment in the rear area. The heat absorbed by the refrigerant is flowing through the refrigerant-refrigerant heat exchanger 9 as heat of dewatering or condensation heat to the coolant of the first coolant circuit 14 transfer. The first coolant circuit 14 is due to the temperature level of the coolant also as a low-temperature coolant circuit 14 designated. Parallel to the flow path with the operated as an evaporator refrigerant-air heat exchanger 12 and the upstream in the flow direction of the refrigerant expansion device 10 is a flow path with an expansion organ 11 and the downstream in the flow direction of the refrigerant refrigerant-refrigerant heat exchanger 13 of the third coolant circuit 33 educated. The evaporators 12 . 13 be with the upstream in the flow direction of the refrigerant expansion organs 10 . 11 as required individually or in parallel with each other supplied with refrigerant.

The coolant circuits 14 . 20 . 33 each have a coolant pump 16 . 22 . 34 for circulating the coolant. The first coolant circuit 14 Serves with the refrigerant-refrigerant heat exchanger 9 for receiving the heat of dewatering or condensation heat of the refrigerant from the secondary refrigerant circuit 7 , Furthermore, the first coolant circuit 14 as a low-temperature coolant circuit also for removing heat from different components 19 , For example, the electric drive train, such as an internal charger, a transformer, an inverter or the electric drive motor, or used to dissipate heat from the charge air or the transmission oil. The coolant is divided into two different flow paths, each of which is a branch point 17 to an estuary 18 extend, wherein the first flow path, the refrigerant-refrigerant heat exchanger 9 and the coolant through the second flow path to the component to be cooled 19 is directed. The two flow paths are acted upon individually or jointly and in parallel with coolant as needed. For splitting the coolant is the branch point 17 designed as a three-way valve, so that the proportions of the mass flow can be between 0 and 100% as needed. The in the refrigerant-refrigerant heat exchanger 9 or from the component 19 absorbed heat is flowing through a coolant-air heat exchanger 15 discharged to the ambient air. The also referred to as a low-temperature cooler coolant-air heat exchanger 15 is arranged in the front region of the motor vehicle.

The second coolant circuit 20 on the one hand for cooling a drive motor 32 , in particular an internal combustion engine, and when needed for heating the supply air for the front and / or the rear of the passenger compartment used, wherein the coolant to different flow paths 24 . 28 can be split. The second coolant circuit 20 is due to the temperature level of the coolant as a high-temperature coolant circuit 20 designated. The first flow path 24 extends from a branch point 23 to an estuary 25 and has a first heating heat exchanger 26 on. The first heating heat exchanger 26 serves as the evaporator-operated refrigerant-air heat exchanger 6 , for conditioning the air mass flow supplied to the passenger compartment in the front area. In this case, the air mass flow supplied to the front region of the passenger compartment can be cooled and dehumidified as required and reheated or merely cooled and dehumidified or heated.

The second flow path 28 extends from a branch point 27 to an estuary 30 and has a second heating heat exchanger 31 on. The second heating heat exchanger 31 serves as the evaporator-operated refrigerant-air heat exchanger 12 , for conditioning the air mass flow supplied to the passenger compartment in the rear area. In this case, the air mass flow supplied to the rear region of the passenger compartment can be cooled and dehumidified as required and reheated or merely cooled and dehumidified or heated. The heat absorbed by the drive motor can both at least partially through the flow paths 24 . 28 as well as through another flow path with a coolant-air heat exchanger 21 be passed, wherein when flowing through the coolant-air heat exchanger 21 Heat is dissipated to the ambient air. The also referred to as high-temperature cooler coolant-air heat exchanger 21 is arranged in the front region of the motor vehicle. The excess heat of the internal combustion engine designed as a drive motor 32 can be discharged into the ambient air via the high-temperature cooler both in heating mode and in cooling mode. The two flow paths 24 . 28 with the heating heat exchangers 26 . 31 and the flow path with the refrigerant-air heat exchanger 21 can be applied individually or together and in parallel with coolant as required. For dividing and directing the coolant through the first flow path 24 or by the coolant-air heat exchanger 21 is the branch point 23 designed as a three-way valve. For dividing and directing the coolant through the second flow path 28 has the second flow path 28 a shut-off valve 29 on. The proportions of the mass flow of the coolant may be between 0 and 100% as needed.

Designed as an evaporator refrigerant-air heat exchanger 6 . 12 the refrigerant circuits 2 . 7 and the heat exchangers 26 . 31 of high-temperature refrigerant ice skating 20 are each arranged in an air duct such that the air mass flow to be supplied respectively to the passenger compartment of the motor vehicle successively via the heat transfer surfaces of the refrigerant-air heat exchanger 6 . 12 and the heating heat exchanger 26 . 31 flows. According to an alternative embodiment, the refrigerant-air heat exchangers designed as evaporators are 6 . 12 the refrigerant circuits 2 . 7 and the heat exchangers 26 . 31 the high-temperature coolant circuit 20 each arranged in two separately formed air ducts such that each of the passenger compartment of the motor vehicle to be supplied air mass flow, the heat transfer surfaces of the refrigerant-air heat exchanger 6 . 12 and the heating heat exchanger 26 . 31 proportionately parallel to each other and overflowed independently.

With the training of the air conditioning system 1 to 1 it is possible to condition the supply air flows for the front area and the rear area of the passenger compartment as separate zones independently of each other. In addition, there is the possibility of only the heat exchanger 35 as a battery cooler, for example, to use for cooling the high-voltage battery, while the compressor 3 of the primary refrigerant circuit 2 and thus the primary refrigerant cycle 2 is out of order. The heat through the battery coolant circuit 33 , the refrigerant-refrigerant heat exchanger 13 and the refrigerant-refrigerant heat exchanger 9 of the secondary refrigerant circuit 7 as well as the coolant-air heat exchanger 15 the low-temperature coolant circuit 14 transferred indirectly from the high-voltage battery to the ambient air. Due to an optimal arrangement of components compressor 8th , coolant cooled condenser / gas cooler 9 , Expansion organs 10 . 11 , as well as the evaporator 12 . 13 of the secondary refrigerant circuit 7 The components are interconnected by minimal length refrigerant lines. By using the refrigerant pipes with a minimum length, on the one hand, the pressure losses of the refrigerant as it flows through the refrigerant pipes are minimized. On the other hand, the weight and the associated costs of the refrigerant pipes are minimal.

The coolant-air heat exchanger 15 the low-temperature coolant circuit 14 , the refrigerant-air heat exchanger 4 of the primary refrigerant circuit 2 and the refrigerant-air heat exchanger 21 the high-temperature coolant circuit 20 are each in the front of the vehicle arranged to transfer the heat to the ambient air. Here are the heat exchangers 15 . 4 . 21 arranged in the flow direction of the ambient air in the order mentioned, so that the coolant-air heat exchanger 15 the low-temperature coolant circuit 14 is flowed directly from the cool ambient air with appropriate temperature. For the sake of the operation of the air conditioning system 1 with maximum efficiency, in terms of the condensation temperature in the secondary refrigerant circuit 7 and the possible charge air cooling, and for component-specific reasons, such as the temperature of the high-voltage battery, is the temperature of the low-temperature coolant circuit 14 circulating coolant as low as possible. The refrigerant-air heat exchanger 4 of the primary refrigerant circuit 2 is in the flow direction of the ambient air after the coolant-air heat exchanger 15 the low-temperature coolant circuit 14 arranged. The temperature of the through the refrigerant-air heat exchanger 4 flowing air may vary depending on the operating mode of the air conditioning system 1 be higher than the temperature of the ambient air, as by the refrigerant-air heat exchanger 4 flowing air when flowing over the coolant-air heat exchanger 15 Heat from the low-temperature coolant circuit 14 has recorded. The coolant-air heat exchanger 21 the high-temperature coolant circuit 20 is in the flow direction of the ambient air after the refrigerant-air heat exchanger 4 of the primary refrigerant circuit 2 arranged. The through the coolant-air heat exchanger 21 flowing air has depending on the operating mode of the air conditioning system 1 already heat from low-temperature coolant circuit 14 as well as from the primary refrigerant circuit 2 recorded and has a much higher temperature than the ambient air. The drive motor designed as an internal combustion engine 32 generated heat can flow through the coolant-air-heat exchanger 21 nevertheless be released to the air, since the temperature level of the coolant within the high-temperature coolant circuit 20 is significantly higher than the temperature level of the refrigerant at high pressure within the primary refrigerant circuit 2 or the temperature level of the coolant within the low-temperature coolant circuit 14 ,

In 2 is an air conditioning system 1' a motor vehicle, similar to the air conditioning system 1 out 1 , with the first refrigerant circuit 2 for conditioning the supply air for the front area of the passenger compartment and the second refrigerant circuit 7 for conditioning the supply air to the rear of the passenger compartment. Also the air conditioning system 1' indicates the first coolant circuit 14 for receiving heat from the second refrigerant circuit 7 , the second coolant circuit 20 for cooling the drive motor 32 and, if necessary, for heating the supply air for the front and the rear of the passenger compartment. In contrast to the air conditioning system 1 according to 1 is the air conditioning system 1' according to 2 with a heat exchanger 35 ' designed for cooling the battery, which directly with the secondary refrigerant circuit 7 thermally coupled. Instead of the battery coolant circuit 33 which is via the refrigerant-refrigerant heat exchanger 13 with the secondary refrigerant circuit 7 is coupled, the battery in the air conditioning system 1' with the heat exchanger 35 ' directly refrigerated. The evaporator 13a of the secondary refrigerant circuit 7 and the battery cooler 35 ' are formed as a one-piece component.

The air conditioning system 1' with the direct refrigerant-cooled heat exchanger 35 ' offers compared to the air conditioning system 1 out 1 Higher efficiency in operation, as the waste heat from the battery is transferred directly to the refrigerant. For indirect cooling of the battery of the air conditioning system 1 The heat is transferred via the coolant of the battery coolant circuit 33 as an intermediate medium. The functions of the air conditioning system 1 and the air conditioning system 1' are identical.

3 shows an air conditioning system 1'' a motor vehicle, similar to the air conditioning system 1 out 1 , with a first refrigerant circuit 2 '' for conditioning the supply air for the front area of the passenger compartment and the second refrigerant circuit 7 '' for conditioning the supply air for the rear area of the passenger compartment. Also the air conditioning system 1'' indicates the first coolant circuit 14 for receiving heat from the second refrigerant circuit 7 '' , the second coolant circuit 20 for cooling the drive motor 32 and if necessary, for heating the supply air for the front and the rear of the passenger compartment and a third coolant circuit 33 '' with a heat exchanger 35 for cooling the electrical component, such as the high-voltage battery. In contrast to the air conditioning system 1 according to 1 is the third coolant circuit 33 '' the air conditioning system 1'' according to 3 via a refrigerant-refrigerant heat exchanger operated as an evaporator 13 '' , which is also referred to as a chiller, with the first refrigerant circuit 2 '' and not with the second refrigerant circuit 7 '' thermally coupled. Parallel to the flow path with the operated as an evaporator refrigerant-air heat exchanger 6 and the upstream expansion organ 5 is a flow path with an expansion organ 11 '' and the downstream refrigerant-refrigerant heat exchanger 13 '' of the third coolant circuit 33 '' educated. The evaporators 6 . 13 '' be upstream with the upstream in the flow direction of the refrigerant expansion organs 5 . 11 '' as required individually or in parallel with each other supplied with refrigerant.

The training of the air conditioning system 1'' can be provided especially for motor vehicles with a hybrid drive, in which the high-voltage battery is arranged in the front region of the motor vehicle. According to an alternative embodiment not shown, the heat exchanger for cooling the battery is directly connected to the primary refrigerant circuit 2 '' thermally coupled. Instead of the battery coolant circuit 33 '' which is via the refrigerant-refrigerant heat exchanger 13 '' with the primary refrigerant circuit 2 '' is connected, the battery is cooled directly with the heat exchanger refrigerant. The refrigerant-refrigerant heat exchanger of the primary refrigerant circuit 2 '' and the battery cooler are formed as a one-piece component.

In 4 is an air conditioning system 1''' a motor vehicle, similar to the air conditioning system 1 out 1 , with the first refrigerant circuit 2 for conditioning the supply air for the front area of the passenger compartment and the second refrigerant circuit 7 for conditioning the supply air to the rear of the passenger compartment. Also the air conditioning system 1''' indicates the first coolant circuit 14 for receiving heat from the second refrigerant circuit 7 '' , the second coolant circuit 20 for cooling the drive motor 32 and, if necessary, for heating the supply air for the front and the rear of the passenger compartment. In contrast to the air conditioning system 1 according to 1 has the air conditioning system 1''' according to 4 no third coolant circuit 33 and no battery cooler 35 for cooling the high-voltage battery.

The air conditioning system 1''' is provided for thermal management and for cooling a passenger compartment of a motor vehicle with pure internal combustion engine drive. The lack of electrical drive components eliminates the need for direct or indirect cooling of the high-voltage battery. The training of the air conditioning system 1''' is particularly easy to integrate in motor vehicles with indirect charge air cooling. In this case, the low-temperature coolant circuit 14 with the refrigerant-refrigerant heat exchanger 9 both for receiving the heat of dewatering or condensation heat of the refrigerant from the secondary refrigerant circuit 7 '' used as well as for indirect intercooling and transmission oil cooling.

5 shows an air conditioning system 1'''' a motor vehicle, similar to the air conditioning system 1 out 1 , with a first refrigerant circuit 2 for conditioning the supply air for the front area of the passenger compartment and the second refrigerant circuit 7 for conditioning the supply air for the rear area of the passenger compartment. Also the air conditioning system 1'''' has a first coolant circuit 14 '''' for receiving heat from the second refrigerant circuit 7 , the second coolant circuit 20 for cooling the drive motor 32 and if necessary, for heating the supply air for the front and the rear of the passenger compartment and a third coolant circuit 33 with a heat exchanger 35 for cooling the electrical component, such as the high-voltage battery. In contrast to the air conditioning system 1 according to 1 is with the air conditioning system 1'''' according to 5 a third refrigerant circuit 36 designed as another secondary refrigerant circuit. The third refrigerant circuit 36 is about as a condenser / gas cooler 38 operated refrigerant-refrigerant heat exchanger 38 with the first coolant circuit 14 '''' thermally coupled.

The third refrigerant circuit 36 has a compressor in the flow direction of the refrigerant 37 , the refrigerant-refrigerant heat exchanger 38 , an expansion organ 39 and operated as an evaporator refrigerant-air heat exchanger 40 on. That from the evaporator 40 escaping refrigerant is from the compressor 37 sucked. The refrigerant circuit 36 is closed.

The first coolant circuit 14 '''' thus serves in addition to receiving the heat of dewatering or condensation heat of the refrigerant from the secondary refrigerant circuit 7 and dissipating heat from different components 19 the motor vehicle and the inclusion of the heat of dewatering or condensation heat of the refrigerant from the secondary refrigerant circuit 36 , The coolant is divided into different flow paths. Next to the branch off 17 to the estuary 18 extending first flow path with the refrigerant-refrigerant heat exchanger 9 and from a branch point 41 to an estuary 42 extending second flow path for cooling components 19 of the motor vehicle is the first coolant circuit 14 '''' with a third flow path with the refrigerant-refrigerant heat exchanger 38 educated. The flow paths are acted upon individually or in parallel with coolant as needed. For splitting the coolant are the branch points 17 . 41 each designed as three-way valves, so that the proportions of the mass flow of the coolant can be between 0 and 100% as needed. In the refrigerant-refrigerant heat exchangers 9 . 38 or from the component nineteen absorbed heat is flowing through the coolant-air heat exchanger 15 discharged to the ambient air.

The air conditioning system may also be formed with other secondary refrigerant circuits, not shown. After further alternative embodiments, not shown, are the air conditioning systems 1' . 1'' . 1''' from the 2 to 4 also formed with at least one further secondary refrigerant circuit.

Out 6 goes an air conditioning system 1''''' a motor vehicle, similar to the air conditioning system 1 out 1 , with a first refrigerant circuit 2 ''''' for conditioning the supply air for the front area of the passenger compartment and the second refrigerant circuit 7 ''''' for conditioning the supply air to the rear of the passenger compartment. Also the air conditioning system 1''''' indicates the first coolant circuit 14 for receiving heat from the second refrigerant circuit 7 ''''' , the second coolant circuit 20 for cooling the drive motor 32 and if necessary, for heating the supply air for the front and the rear of the passenger compartment and a third coolant circuit 33 with a heat exchanger 35 for cooling the electrical component, such as the high-voltage battery.

In the air conditioning system 1''''' out 6 were compared to the air conditioning system 1 the primary refrigerant circuit 2 ''''' and the secondary refrigerant circuit 7 ''''' each around an internal heat exchanger 43 . 44 extended. The internal heat exchanger 43 . 44 are to be understood as in-circuit heat exchanger, which are used for heat transfer between the refrigerant at high pressure and the refrigerant at low pressure. That from the heat exchanger 43 . 44 High-temperature refrigerant leaks into the condenser / gas cooler after liquefaction 4 . 9 further cooled or supercooled while at the same time from the evaporator 6 . 12 . 13 escaping, present as suction refrigerant before entering the compressor 3 . 8th is overheated.

By using the internal heat exchanger 43 . 44 can be the cooling capacity and the efficiency of the air conditioning system 1''''' increase. In particular, when using the refrigerant R744 is by the use of the internal heat exchanger 43 . 44 significantly increases the cooling capacity.

In an alternative embodiment, not shown, the air conditioning system has the internal heat exchanger either within the primary refrigerant circuit or within the secondary refrigerant circuit. After further alternative embodiments, not shown, are the air conditioning systems 1' . 1'' . 1''' . 1'''' from the 2 to 5 and the respectively associated embodiments not shown also formed with at least one internal heat exchanger.

LIST OF REFERENCE NUMBERS

1, 1 ', 1' ', 1' ''

 Cooling system

1 '' '', 1 '' '' '

 Cooling system

2, 2 '', 2 '' '' '

 first refrigerant circuit, primary refrigerant circuit

3

Compressor primary refrigerant circuit 2

4

 Refrigerant air heat exchanger, condenser / gas cooler

5

 expansion element

6

 Refrigerant-air heat exchanger, evaporator

7, 7 '', 7 '' '' '

 second refrigerant circuit, secondary refrigerant circuit

8th

Compressor secondary refrigerant circuit 7

9

 Refrigerant-refrigerant heat exchanger, condenser / gas cooler

10, 11, 11 ''

 expansion element

12

 Refrigerant-air heat exchanger, evaporator

13, 13 ''

 Refrigerant-refrigerant heat exchanger, evaporator

13a

 Evaporator

14, 14 '' ''

 first coolant circuit, low-temperature coolant circuit

15

 Refrigerant-air heat exchanger

16

Coolant pump low-temperature coolant circuit 14

17

 branching point

18

 opening point

19

 component

20

 second coolant circuit, high-temperature coolant circuit

21

 Refrigerant-air heat exchanger

22

Coolant pump High-temperature coolant circuit 20

23

Three-way valve, branch point first flow path 24

24

first flow path high temperature coolant circuit 20

25

Mouth point first flow path 24

26

 first heating heat exchanger

27

 branching point

28

second flow path high-temperature coolant circuit 20

29

 shut-off valve

30

Mouth point second flow path 28

31

 second heating heat exchanger

32

 drive motor

33, 33 ''

 third coolant circuit, battery coolant circuit

34

Coolant pump Battery coolant circuit 20

35, 35 '

 Heat exchanger, battery cooler

36

 third refrigerant circuit, second secondary refrigerant circuit

37

Compressor secondary refrigerant circuit 36

38

 Refrigerant-refrigerant heat exchanger, condenser / gas cooler

39

 expansion element

40

 Refrigerant-air heat exchanger, evaporator

41

 branching point

42

 opening point

43, 44

 internal heat exchanger

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• US 7228707 B2 [0005, 0005]
• US 2013/0145781 A1 [0005, 0005]

Claims (12)

Air conditioning system ( 1 . 1' . 1'' . 1''' . 1'''' . 1''''' ) for a motor vehicle, comprising - at least one first refrigerant circuit ( 2 . 2 '' . 2 ''''' ) and a second refrigerant circuit ( 7 . 7 '' . 7 ''''' ) for the independent conditioning of a passenger compartment to be supplied air mass flows, each with a compressor ( 3 . 8th ), as a condenser / gas cooler ( 4 . 9 ) operated heat exchanger, at least one expansion organ ( 5 . 10 . 11 . 11 '' ) and at least one as an evaporator ( 6 . 12 . 13 . 13a . 13 '' ) operated heat exchanger - at least a first coolant circuit ( 14 . 14 '''' ) and a second coolant circuit ( 20 ), characterized in that - the condenser / gas cooler ( 4 ) of the first refrigerant circuit ( 2 . 2 '' . 2 ''''' ) as a refrigerant-air heat exchanger ( 4 ) for the transfer of heat to the ambient air and - the condenser / gas cooler ( 9 ) of the second refrigerant circuit ( 7 . 7 '' . 7 ''''' ) as a refrigerant-refrigerant heat exchanger ( 9 ) for transferring heat to the first coolant circuit ( 14 . 14 '''' ), wherein the first coolant circuit ( 14 . 14 '''' ) is designed as a low-temperature coolant circuit. Air conditioning system ( 1 . 1' . 1'' . 1''' . 1'''' . 1''''' ) according to claim 1, characterized in that the second coolant circuit ( 20 ) for cooling a drive motor ( 32 ) is designed as a high-temperature coolant circuit and at least one heating heat exchanger ( 26 . 31 ) for conditioning at least one air mass flow to be supplied to the passenger compartment and a coolant / air heat exchanger ( 21 ) for transmitting heat to the ambient air. Air conditioning system ( 1 . 1' . 1'' . 1''' . 1'''' . 1''''' ) according to claim 2, characterized in that the second coolant circuit ( 20 ) a first flow path ( 24 ) with a first heating heat exchanger ( 26 ) and a second flow path ( 28 ) with a second heating heat exchanger ( 31 ) each for transmitting heat to the incoming air of the passenger compartment, wherein the flow paths ( 24 . 28 ) each from a branch point ( 23 . 27 ) to an estuarine site ( 25 . 30 ) and can be acted upon independently with coolant. Air conditioning system ( 1 . 1' . 1'' . 1''' . 1'''' . 1''''' ) according to one of claims 1 to 3, characterized in that the first coolant circuit ( 14 . 14 '''' ) for receiving heat from the second refrigerant circuit ( 7 . 7 '' . 7 ''''' ) with the refrigerant-refrigerant heat exchanger ( 9 ) and for absorbing heat from heat-generating components ( 19 ) of the motor vehicle is designed with different flow paths, and a coolant-air heat exchanger ( 15 ) for transferring heat to the ambient air, wherein the flow paths each from a branch point ( 17 ) to an estuarine site ( 18 ) and can be acted upon independently with coolant. Air conditioning system ( 1 . 1'' . 1'''' . 1''''' ) According to one of claims 1 to 4, characterized in that a third coolant circuit ( 33 . 33 '' ) with a heat exchanger ( 35 ) for transferring heat to the coolant and a refrigerant-refrigerant heat exchanger (FIG. 13 . 13 '' ) is configured to transfer heat to the refrigerant. Air conditioning system ( 1 . 1'' . 1'''' . 1''''' ) according to claim 5, characterized in that the refrigerant-refrigerant heat exchanger ( 13 . 13 '' ) for transferring heat to the refrigerant as a component of the second refrigerant circuit ( 7 . 7 ''''' ) or as a component of the first refrigerant circuit ( 2 . 2 '' ) is trained. Air conditioning system ( 1' ) according to one of claims 1 to 4, characterized in that a heat exchanger ( 35 ' ) in combination with an evaporator ( 13a ) is designed for a refrigerant heat exchanger designed for the direct transfer of heat to the refrigerant. Air conditioning system ( 1' ) according to claim 7, characterized in that the evaporator ( 13a ) as a component of the second refrigerant circuit ( 7 ) or as a component of the first refrigerant circuit ( 2 ) is trained. Air conditioning system ( 1 . 1' . 1'' . 1''' . 1'''' . 1''''' ) according to one of claims 1 to 8, characterized in that at least one refrigerant circuit ( 2 '' . 2 ''''' 7 . 7 ''''' ) two flow paths with one each as an evaporator ( 6 . 12 . 13 . 13a . 13 '' ) operated heat exchanger and upstream in the flow direction of the refrigerant expansion element ( 5 . 10 . 11 . 11 '' ), wherein the flow paths are arranged parallel to each other and can be acted upon individually or in parallel to each other with refrigerant as needed. Air conditioning system ( 1''''' ) according to one of claims 1 to 9, characterized in that at least one of the refrigerant circuits ( 2 ''''' . 7 ''''' ) an internal heat exchanger ( 43 . 44 ) for heat transfer between the refrigerant at high pressure and the refrigerant at low pressure. Air conditioning system ( 1'''' ) according to one of claims 1 to 10, characterized in that at least one third refrigerant circuit ( 36 ) when Secondary refrigerant circuit with a compressor ( 37 ), as a condenser / gas cooler ( 38 ) operated heat exchanger, at least one expansion organ ( 39 ) and at least one as an evaporator ( 40 ) is designed, wherein the condenser / gas cooler ( 38 ) as a refrigerant-refrigerant heat exchanger ( 38 ) for transferring heat to the first coolant circuit ( 14 '''' ) is trained. Air conditioning system ( 1'''' ) according to claim 11, characterized in that the first coolant circuit ( 14 '''' ) for receiving heat from the second refrigerant circuit ( 7 ) with the refrigerant-refrigerant heat exchanger ( 9 ), for absorbing heat from heat-generating components ( 19 ) of the motor vehicle and for absorbing heat from the third refrigerant circuit ( 36 ) with the refrigerant-refrigerant heat exchanger ( 38 ) is formed with different flow paths, wherein the flow paths each from a branch point ( 17 . 41 ) to an estuarine site ( 18 . 42 ) and can be acted upon independently with coolant.

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