Refrigerant circuit with distribution valve upstream of evaporator and chiller, motor vehicle and method for operating a refrigerant circuit

Abstract

The invention relates to a refrigerant circuit (10) for a motor vehicle, comprising a compressor (14) which, in heat pump operation, supplies a partial flow of compressed refrigerant to a heat exchanger (16) by means of which an airflow (18) introduced into a passenger compartment can be heated. A further partial flow of compressed refrigerant can be supplied to a refrigerant cooler (22) which is supplied with ambient air (24). The refrigerant circuit (10) comprises a first valve (28) which is arranged downstream of a refrigerant outlet (26) of the heat exchanger (16) and a second valve (30) which is arranged downstream of a refrigerant outlet (32) of the refrigerant cooler (22). The refrigerant circuit (10) comprises a distribution valve (34) to which partial flows of refrigerant from the two valves (28, 30) can be supplied.A first evaporator (38) can be supplied with expanded refrigerant via a first outlet (36) of the distribution valve (34), and a second evaporator (42) can be supplied via a second outlet (40) of the distribution valve (34). The invention also relates to a motor vehicle and a method (10) for operating the refrigerant circuit (10).

Description

[0001] The invention relates to a refrigerant circuit for a motor vehicle, comprising a compressor configured to supply at least a partial flow of compressed refrigerant to a heat exchanger of the refrigerant circuit during heat pump operation. The heat exchanger is configured to heat an airflow that can be introduced into a passenger compartment of the motor vehicle during heat pump operation. The refrigerant circuit includes a refrigerant cooler, separate from the heat exchanger, which can be cooled by ambient air. At least a partial flow of compressed refrigerant can be supplied to the refrigerant cooler. Furthermore, the invention relates to a motor vehicle with such a refrigerant circuit and a method for operating a refrigerant circuit.

[0002] The control of refrigerant circuits, such as those used in motor vehicles, is becoming increasingly complex. Furthermore, particularly when using R744 (carbon dioxide) as a refrigerant, it is essential to design the components of the refrigerant circuit to be sufficiently robust. For example, it is crucial that the components can withstand the high pressures that occur during operation of the refrigerant circuit with R744. This makes the refrigerant circuit costly. Therefore, it is advantageous to reduce the number of components in the refrigerant circuit, while retaining existing functions of the refrigerant circuit wherever possible.

[0003] Due to different operating modes and strategies for operating the refrigerant circuit, there are also opportunities to redesign parts or components of the refrigerant circuit. It is desirable that the new parts cover the same range of functions as existing parts or components in the refrigerant circuit.

[0004] DE 10 2012 111 975 A1 describes an air conditioning system for a motor vehicle with a refrigerant circuit and an engine cooling circuit. In heat pump mode, a heat exchanger located in the front of the vehicle and a heat exchanger also known as a chiller can be supplied with refrigerant, so that both the ambient air and the coolant of the engine cooling circuit can be used as heat sources.

[0005] DE 10 2020 106 625 A1 describes a post-heating method for operating a refrigeration system for a motor vehicle.

[0006] German patent DE 10 2015 002 165 A1 describes a vehicle air conditioning system with reheat operation. In refrigeration mode, a first changeover valve opens. This allows refrigerant compressed by a refrigerant compressor to be fed to a gas cooler located at the front of the vehicle. In heating and reheat mode, with the first changeover valve closed, the compressed refrigerant is fed to a heat exchanger via an open second changeover valve. The heat exchanger is integrated into a heating circuit, which includes a heating heat exchanger. At the heating heat exchanger, an airflow supplied to the passenger compartment is reheated after being cooled by an evaporator.

[0007] Another system for thermal management of a vehicle is described in DE 10 2015 103 032 A1.

[0008] The object of the present invention is to provide a refrigerant circuit of the type mentioned at the outset, which is easy to operate and requires little effort, as well as to provide a motor vehicle with the refrigerant circuit and a corresponding method for operating the refrigerant circuit.

[0009] This problem is solved by a refrigerant circuit with the features of claim 1, a motor vehicle with the features of claim 6, and a method with the features of claim 7. Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims and in the following description.

[0010] The refrigerant circuit according to the invention for a motor vehicle comprises a compressor configured to supply at least a partial flow of compressed refrigerant to a heat exchanger of the refrigerant circuit during heat pump operation. The heat exchanger is configured to heat an airflow that can be introduced into a passenger compartment of the motor vehicle during heat pump operation. The refrigerant circuit includes a refrigerant cooler, separate from the heat exchanger, which can be exposed to ambient air. At least a partial flow of compressed refrigerant can be supplied to the refrigerant cooler. The refrigerant circuit includes a first valve, which is arranged downstream of a refrigerant outlet of the heat exchanger, and by means of which the pressure of the refrigerant in the heat exchanger can be adjusted.The first valve is designed as an expansion device with a variable cross-section through which the refrigerant flows. The refrigerant circuit includes a second valve, located downstream of a refrigerant outlet of the refrigerant cooler, which allows the refrigerant pressure in the cooler to be adjusted. This second valve is also designed as an expansion device with a variable cross-section through which the refrigerant flows. The refrigerant circuit includes a distribution valve to which partial refrigerant flows from the first and second valves can be supplied. A first evaporator of the refrigerant circuit can be supplied with expanded refrigerant via a first outlet of the distribution valve, and a second evaporator of the refrigerant circuit can be supplied with expanded refrigerant via a second outlet of the distribution valve.

[0011] The refrigerant circuit features an additional distribution valve at a branch point, from which a first partial flow of the compressed refrigerant can be supplied to the heat exchanger and a second partial flow to the refrigerant cooler. This additional distribution valve allows for adjustment of the respective partial flows. As a result, shut-off valves are not required in the lines leading from the compressor to the heat exchanger on the one hand and to the refrigerant cooler on the other. These shut-off valves would otherwise be necessary to control the flow of compressed refrigerant to the heat exchanger or the refrigerant cooler. By replacing these shut-off valves, the refrigerant circuit is designed with minimal complexity.Furthermore, the use of the additional distribution valve at the branch point facilitates the operation of the refrigerant circuit. This is because a control device for the refrigerant circuit can actuate the additional distribution valve to adjust the partial flows.

[0012] The additional distribution valve is designed to simultaneously supply partial flows of the compressed refrigerant to the heat exchanger and the refrigerant cooler. This allows heat to be dissipated from the compressed refrigerant at both the heat exchanger and the refrigerant cooler. This is particularly advantageous when, during heat pump operation, there is an excess of heat transferred into the refrigerant relative to the heating output to be provided by the heat exchanger. In such cases, this excess heat can be easily released to the ambient air via the refrigerant cooler.

[0013] The refrigerant circuit's control unit is designed to adjust the flow rate of the partial flow supplied to the refrigerant cooler by controlling the additional distribution valve, depending on the excess heat generated at the heat exchanger. Because the refrigerant cooler is supplied with this partial flow, the excess heat from the refrigerant can be easily dissipated via the ambient air, which the cooler can be exposed to. This ensures that the heat exchanger provides precisely the heating capacity required to warm the airflow supplied to the vehicle's passenger compartment.

[0014] The control device is designed to control the first valve, the second valve, the distribution valve and the compressor according to the respective requirements.

[0015] The inclusion of the distribution valve makes supplying the first and / or second evaporator with the expanded refrigerant very easy. Consequently, the refrigerant circuit is particularly easy to operate. Both setting high pressure in the heat exchanger and high pressure in the refrigerant cooler, as well as expanding the refrigerant, can be easily achieved using the first and second valves located upstream of the distribution valve. Furthermore, the refrigerant circuit is significantly simpler and less complex in design than a circuit where, downstream of a junction where the partial refrigerant flows from the two valves converge, the refrigerant flows are expanded by a separate expansion valve located upstream of each evaporator.

[0016] The refrigerant circuit, which features a distribution valve with a first and second outlet, omits both a first expansion valve upstream of the first evaporator and downstream of the junction, and a second expansion valve upstream of the second evaporator and downstream of the junction. This is based on the understanding that the distribution valve, with its single inlet and two outlets, can very easily replace such complex expansion valves. This is advantageous, particularly with regard to the simplified setup of the refrigerant circuit. Furthermore, the distribution valve can be reliably and consistently controlled by a control unit of the refrigerant circuit, which facilitates the simple operation of the refrigerant circuit.

[0017] Eliminating the two expansion valves located downstream of the junction, which are upstream of the first and second evaporators respectively, advantageously results in cost savings. Furthermore, the use of the distribution valve advantageously enables simple and stringent control of the refrigerant circuit.

[0018] The pressure in the heat exchanger is adjusted via the first valve, and the pressure in the refrigerant cooler is adjusted via the second valve. During heat pump operation, the refrigerant circuit is controlled by actuating the two valves accordingly. The compressor is active during this process. In heat pump operation, the compressor compresses the refrigerant, thus providing high pressure on its pressure side.

[0019] Preferably, the distribution valve is designed to supply the first evaporator with expanded refrigerant via the first outlet and simultaneously supply the second evaporator with expanded refrigerant via the second outlet. This allows the distribution valve to be effectively used as a mixing valve, enabling variable adjustment of the partial flows supplied to each evaporator. This makes it particularly easy to accommodate the cooling objectives to be achieved by the evaporators.

[0020] Preferably, the first evaporator in the heat pump operation is designed to dehumidify the airflow that can be introduced into the passenger compartment.

[0021] In heat pump operation, the airflow previously dehumidified at the first evaporator can therefore preferably be reheated by means of the heat exchanger. This is particularly advantageous for limiting or keeping the humidity low in the passenger compartment of the vehicle when the refrigerant circuit is installed in the vehicle and operated in heat pump mode.

[0022] Such a heat pump operation, in which the airflow dehumidified at the first evaporator is reheated by means of the heat exchanger, is usually referred to as reheat operation. However, even in this reheat operation, the first evaporator is used as a heat source, since heat from the airflow is transferred to the refrigerant at the first evaporator. Therefore, the reheat operation can also be described as a heat pump operation.

[0023] Preferably, the second evaporator is designed as a chiller through which the refrigerant and a coolant flow. The chiller allows the liquid coolant to be cooled particularly effectively, making it very suitable for cooling purposes. This is advantageous. For example, the coolant can be used to cool an electrical energy storage device in a motor vehicle if the refrigerant circuit is installed in the vehicle.

[0024] Preferably, the refrigerant circuit can be operated in cooling mode, in which the refrigerant compressed by the compressor is fed exclusively to the refrigerant cooler. In cooling mode, the refrigerant supplied to the first evaporator and / or the second evaporator can be depressurized by means of the second valve. Furthermore, in cooling mode, the refrigerant flow direction through the refrigerant cooler is the same as in heat pump mode. This is particularly advantageous for the simple operation of the refrigerant circuit. Controlling the refrigerant circuit in both cooling and heat pump modes is especially easy when the refrigerant always flows through the refrigerant cooler in the same direction.Furthermore, this unidirectional flow through the refrigerant cooler is conducive to the low-effort and cost-effective provision of the refrigerant circuit.

[0025] Preferably, the refrigerant flows through the heat exchanger in the same direction in every operating state of the refrigerant circuit in which refrigerant flows through the heat exchanger. Analogous to the unidirectional flow through the refrigerant cooler described, this is advantageous for the cost-effective provision and simple operation of the refrigerant circuit.

[0026] The motor vehicle according to the invention has the refrigerant circuit according to the invention. This allows the simple operation of the low-effort refrigerant circuit in the motor vehicle to be used advantageously.

[0027] Preferably, the motor vehicle is designed as an electric vehicle or a hybrid vehicle. Particularly in such a vehicle, it is advantageous if the heat pump operation of the refrigerant circuit can provide thermal comfort for the occupants of the passenger compartment simply and reliably.

[0028] When an electrical energy storage device of an electric vehicle or hybrid vehicle is designed as a high-voltage battery, the electrical energy storage device has a nominal voltage of more than 60 volts and, in particular, of up to several hundred volts.

[0029] In the inventive method for operating a refrigerant circuit for a motor vehicle, a compressor of the refrigerant circuit, operating in heat pump mode, supplies at least a partial flow of compressed refrigerant to a heat exchanger of the refrigerant circuit. The heat exchanger is designed to heat an airflow that can be introduced into a passenger compartment of the motor vehicle during heat pump operation. The refrigerant circuit includes a refrigerant cooler, separate from the heat exchanger, which is open to ambient air. A partial flow of compressed refrigerant is supplied to the refrigerant cooler. The refrigerant circuit includes a first valve, which is arranged downstream of a refrigerant outlet of the heat exchanger, and by means of which the pressure of the refrigerant in the heat exchanger is set.The first valve is designed as an expansion device with a variable cross-section through which the refrigerant flows. The refrigerant circuit includes a second valve, located downstream of a refrigerant outlet of the refrigerant cooler, which regulates the refrigerant pressure within the cooler. This second valve is also designed as an expansion device with a variable cross-section through which the refrigerant flows. The refrigerant circuit includes a distribution valve to which partial refrigerant flows from the first and second valves are fed. A first evaporator of the refrigerant circuit is supplied with expanded refrigerant via a first outlet of the distribution valve. Additionally or alternatively, a second evaporator of the refrigerant circuit is supplied with expanded refrigerant via a second outlet of the distribution valve.The refrigerant circuit has a further distribution valve at a branch point, from which a first partial flow of the compressed refrigerant is supplied to the heat exchanger and a second partial flow of the compressed refrigerant is supplied to the refrigerant cooler. This additional distribution valve regulates the respective partial flows. The additional distribution valve simultaneously supplies partial flows of the compressed refrigerant to the heat exchanger and the refrigerant cooler. A control device for the refrigerant circuit, depending on the excess heat generated at the heat exchanger, adjusts the volume of the partial flow supplied to the refrigerant cooler by actuating the additional distribution valve. The control device actuates the first valve, the second valve, the distribution valve, and the compressor according to the respective requirements.

[0030] The use of the distribution valve allows for the simple and efficient use of each evaporator for introducing heat into the refrigerant during heat pump operation. This is advantageous.

[0031] The advantages and preferred embodiments described for the refrigerant circuit according to the invention apply analogously to the motor vehicle according to the invention as well as to the method according to the invention and vice versa.

[0032] The invention therefore also includes further developments of the motor vehicle and the method according to the invention, which have features as already described in connection with the further developments of the refrigerant circuit according to the invention. For this reason, the corresponding further developments of the motor vehicle and the method according to the invention are not described again here.

[0033] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus.

[0034] The invention also includes combinations of the features of the described embodiments. The invention therefore also includes realizations that each exhibit a combination of the features of several of the described embodiments, provided that the embodiments have not been described as mutually exclusive.

[0035] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1. Schematically, a refrigerant circuit for a motor vehicle, in which a distribution valve or mixing valve is arranged upstream of a first evaporator and a second evaporator designed as a chiller; and Fig. 2 highly schematically the motor vehicle which the refrigerant circuit according to Fig. 1.

[0036] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and each further develops the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0037] In the figures, identical reference symbols denote functionally equivalent elements.

[0038] In Fig. Figure 1 shows a refrigerant circuit 10 as it is used in a Fig. The refrigerant circuit 10 can be used in the motor vehicle 12 shown in Figure 2. The refrigerant circuit 10 comprises a compressor 14, which can be used in heat pump operation of the refrigerant circuit 10 to supply compressed refrigerant to a heat exchanger 16 of the refrigerant circuit 10. When the refrigerant circuit 10 is installed in the motor vehicle 12, the heat exchanger 16 is designed to heat an airflow 18 in heat pump operation, which is then supplied to a passenger compartment 20 of the motor vehicle 12 (see Figure 2). Fig. 2) can be introduced. The airflow 18 flowing through or over the heat exchanger 16 is in Fig. 1 schematically illustrated by an arrow.

[0039] The refrigerant circuit 10 comprises a refrigerant cooler 22, separate from the heat exchanger 16, which can be supplied with ambient air 24. For this purpose, the refrigerant cooler 22 is preferably located in a front area 56 (compare Fig. 2) of the motor vehicle 12, i.e., located in the area of ​​the front of the motor vehicle 12.

[0040] The ambient air 24 flowing through or over the refrigerant cooler 22 is also in Fig. 1 is schematically illustrated by an arrow. The respective fans for conveying the airflow 18 to be introduced into the passenger compartment 20 and for supplying the refrigerant cooler 22 with ambient air 24 are located in Fig. 1 not shown in detail for the sake of clarity.

[0041] It can be provided that, in heat pump operation, a first partial flow of the refrigerant conveyed and compressed by the compressor 14 is supplied to the heat exchanger 16, while simultaneously a second partial flow of the compressed refrigerant is supplied to the refrigerant cooler 22. Such heat pump operation of the refrigerant circuit 10 can be provided in particular when the refrigerant contains more heat than is required to provide a predetermined heating output by the heat exchanger 16. The predetermined heating output, or the heating output to be provided by the heat exchanger 16, can, for example, be specified by an occupant of the passenger compartment 20 by operating a (not shown) control device of the motor vehicle 12.

[0042] Downstream of a refrigerant outlet 26 of the heat exchanger 16, a first valve 28 is arranged, which according to the invention is designed as an expansion device. By means of the first valve 28, which has a variable flow cross-section, the pressure of the refrigerant in the heat exchanger 16 can be set.

[0043] Similarly, the refrigerant circuit 10 has a second valve 30, which is arranged downstream of a refrigerant outlet 32 ​​of the refrigerant cooler 22. According to the invention, the second valve 30 is also designed as an expansion device, which has a variable cross-section through which the refrigerant flows. The pressure of the refrigerant in the refrigerant cooler 22 can be adjusted by means of the second valve 30.

[0044] The refrigerant circuit 10 has a first distribution valve 34, to which partial flows of refrigerant from the first valve 28 and the second valve 30 can be supplied. A first evaporator 38 of the refrigerant circuit 10 can be supplied with expanded refrigerant via a first outlet 36 of the first distribution valve 34.

[0045] A second evaporator of the refrigerant circuit 10 can be supplied with expanded refrigerant via a second outlet 40 of the distribution valve 34, wherein the second evaporator is operated according to Fig. 1 is configured as a chiller 42. The chiller 42 is permeable to both the refrigerant and a coolant. The chiller 42 is therefore integrated into both the refrigerant circuit 10 and a coolant circuit 44, with the coolant circuit 44 being in Fig. 1 is only shown schematically and in excerpts.

[0046] The refrigerant coming from the two valves 28 and 30 can enter the first distribution valve 34 via an inlet 46. The first distribution valve 34 is thus designed as a multi-way valve, specifically a three-way valve, by means of which the partial flows of the expanded refrigerant to be supplied to the evaporator 38 on the one hand and the chiller 42 on the other hand can be variably adjusted.

[0047] The first evaporator 38 is designed as an interior evaporator. Accordingly, the airflow 18 can be cooled and dehumidified by means of the first evaporator 38, which is then reheated in heat pump operation by means of the heat exchanger 16. For this purpose, the first evaporator 38 and the heat exchanger 16 are preferably arranged in an air conditioning unit (not shown) of the motor vehicle 12. The air conditioning unit can, in particular, be housed in an instrument panel (not shown) of the motor vehicle 12.

[0048] Due to the inclusion of the first distribution valve 34 in the refrigerant circuit 10, the additional valves located upstream of the evaporator 38 and the chiller 42, respectively, can be omitted. By eliminating these two valves and replacing them with the first distribution valve 34, the refrigerant circuit 10 is easier to operate and also has a simpler design.

[0049] The coolant, which can be cooled by means of the chiller 42 and flows through the coolant circuit 44, can be used, for example, to power an electrical energy storage device 48 and / or an electric drive unit 50 of the motor vehicle 12 (compare Fig. 2) to cool. The at least one electric drive unit 50 is preferably designed to drive wheels 52 of the motor vehicle 12. Accordingly, the motor vehicle 12 can be designed in particular as an electric vehicle or as a hybrid vehicle.

[0050] When chiller 42 is supplied with expanded refrigerant in the heat pump operation of refrigerant circuit 10, the refrigerant cools down in chiller 42. This is because the refrigerant evaporating in chiller 42 extracts heat from the liquid refrigerant.

[0051] In order to introduce heat from the ambient air 24 into the refrigerant during heat pump operation, according to Fig. 1. A cooler 54 is used, which is integrated into the coolant circuit 44 in a manner not shown in detail here. Preferably, the cooler 54, through which the coolant flows, is located in the front area 56 of the motor vehicle 12, as is the refrigerant cooler 22 (see Figure 1). Fig. 2) arranged and exposed to ambient air 24. The refrigerant cooler 22 and the radiator 54 can in particular be combined to form a radiator package, which is arranged in the front area 56 of the motor vehicle 12.

[0052] In heat pump operation, heat contained in the ambient air 24 can be transferred to the refrigerant via the cooler 54. Accordingly, an air source heat pump function of the refrigerant circuit 10 can be implemented via the refrigerant circuit 44, in which the ambient air 24 serves as or is used as a heat source. In particular, it can be provided that the refrigerant cooler 22 is not, or at least only minimally, exposed to refrigerant during air source heat pump operation.

[0053] At a branch point of the refrigerant circuit 10, from which a first partial flow of the compressed refrigerant can be supplied to the heat exchanger 16 and a second partial flow of the compressed refrigerant can be supplied to the refrigerant cooler 22, the refrigerant circuit 10 preferably has a further distribution valve 58. The further distribution valve 58 has an inlet 60 for the compressed refrigerant coming from the compressor 14. The first partial flow of the compressed refrigerant can be supplied to the heat exchanger 16 via a first outlet 62 of the further distribution valve 58. And the second partial flow of the compressed refrigerant can be supplied to the refrigerant cooler 22 via a second outlet 64 of the further distribution valve 58.

[0054] In particular, when there is an excess of heat in the refrigerant during heat pump operation, a control device 66 of the refrigerant circuit 10 can control the additional distribution valve 58 to adjust the size of the partial flow of compressed refrigerant that is supplied to the refrigerant cooler 22 via the additional distribution valve 58. The control device 66 is preferably designed to determine the excess of heat present in the refrigerant during heat pump operation, relative to the heating capacity to be provided by the heat exchanger 16.

[0055] The control device 66 is also designed to adjust or control the two valves 28, 30, the first distribution valve 34 and the compressor 14 according to the respective requirements.

[0056] Advantageously, in the refrigerant circuit 10, both the heat exchanger 16 and the refrigerant cooler 22 are always traversed by the refrigerant in the same flow direction, i.e., unidirectionally. For example, in heat pump operation, the refrigerant always exits the heat exchanger 16 at the refrigerant outlet 26 and the refrigerant cooler 22 at the refrigerant outlet 32, provided that the refrigerant cooler 22 is indeed traversed by refrigerant during heat pump operation.

[0057] Furthermore, the cooling operation of the refrigerant circuit 10 will be explained below. In cooling mode, the refrigerant compressed by the compressor 14 is supplied exclusively to the refrigerant cooler 22 and not to the heat exchanger 16. The refrigerant is then cooled in the refrigerant cooler 22 by means of the ambient air 24. The second valve 30, located downstream of the refrigerant outlet 32 ​​of the refrigerant cooler 22, can be used to expand the refrigerant supplied to the evaporator 38 and / or the chiller 42.

[0058] In this cooling mode, the refrigerant also flows through the refrigerant cooler 22 in the same direction as in heat pump mode, assuming refrigerant flows through the refrigerant cooler 22 at all in heat pump mode. And in this cooling mode as well, the first distribution valve 34 can be used to variably adjust the partial flows of the expanded refrigerant supplied to the evaporator 38 and / or the chiller 42.

[0059] Both the provision of the second distribution valve 58 or mixing valve on the high-pressure side of the refrigerant circuit 10 and the provision of the first distribution valve 34 or mixing valve on the low-pressure side of the refrigerant circuit 10 are advantageous for the simple design of the refrigerant circuit 10. This is because the provision of the additional distribution valve 58 or second distribution valve 58 eliminates the need for separate shut-off valves. Such shut-off valves could alternatively be located in refrigerant lines of the refrigerant circuit 10, which lead from the branch point where the second distribution valve 58 is located to the heat exchanger 16 and the refrigerant cooler 22. Eliminating these shut-off valves in the refrigerant circuit 10 is advantageous.

[0060] As described for the first distribution valve 34 or first mixing valve, the second distribution valve 58 or second mixing valve can also be designed as a multi-way valve, in particular as a three-way valve.

[0061] Overall, the examples show how a topology of the refrigerant circuit 10 can be provided with a parallelization of the refrigerant paths.

Claims

[1] Refrigerant circuit (10) for a motor vehicle (12), comprising a compressor (14) configured to supply at least a partial flow of compressed refrigerant to a heat exchanger (16) of the refrigerant circuit (10) during heat pump operation, wherein the heat exchanger (16) is configured to heat an airflow (18) that can be introduced into a passenger compartment (20) of the motor vehicle (12) during heat pump operation, wherein the refrigerant circuit (10) comprises a refrigerant cooler (22) separate from the heat exchanger (16), which can be supplied with ambient air (24), and wherein at least a partial flow of compressed refrigerant can be supplied to the refrigerant cooler (22). wherein the refrigerant circuit (10) comprises a first valve (28) which is arranged downstream of a refrigerant outlet (26) of the heat exchanger (16), characterized by , that The refrigerant pressure in the heat exchanger (16) can be adjusted by means of the first valve (28), the first valve (28) being designed as an expansion device having a variable cross-section through which the refrigerant flows, the refrigerant circuit (10) comprising a second valve (30) which is arranged downstream of a refrigerant outlet (32) of the refrigerant cooler (22), and by means of which the refrigerant pressure in the refrigerant cooler (22) can be adjusted, the second valve (30) being designed as an expansion device having a variable cross-section through which the refrigerant flows, the refrigerant circuit (10) comprising a distribution valve (34) to which partial flows of the refrigerant from the first valve (28) and from the second valve (30) can be supplied.wherein a first evaporator (38) of the refrigerant circuit (10) can be supplied with expanded refrigerant via a first outlet (36) of the distribution valve (34), wherein a second evaporator (42) of the refrigerant circuit (10) can be supplied with expanded refrigerant via a second outlet (40) of the distribution valve (34), wherein the refrigerant circuit (10) has a further distribution valve (58) at a branch point of the refrigerant circuit (10), from which a first partial flow of the compressed refrigerant can be supplied to the heat exchanger (16) and a second partial flow of the compressed refrigerant can be supplied to the refrigerant cooler (22), by means of which the respective partial flows can be adjusted, wherein the further distribution valve (58) is designed to supply respective partial flows of the compressed refrigerant to the heat exchanger (16) and the refrigerant cooler (22) simultaneously,wherein a control device (66) of the refrigerant circuit (10) is configured to adjust the quantity of the partial flow to be supplied to the refrigerant cooler (22) by controlling the further distribution valve (58), depending on an excess of heat accumulating at the heat exchanger (16), and wherein the control device (66) is configured to control the first valve (28), the second valve (30), the distribution valve (34) and the compressor (14) according to the respective requirements. [2] Refrigerant circuit (10) according to claim 1, characterized by , that the distribution valve (34) is designed to supply the first evaporator (38) with expanded refrigerant via the first outlet (36) and simultaneously supply the second evaporator (42) with expanded refrigerant via the second outlet (40). [3] Refrigerant circuit (10) according to any of the preceding claims, characterized by, that the first evaporator (38) in the heat pump operation is designed to dehumidify the airflow (18) that can be introduced into the passenger compartment (20). [4] Refrigerant circuit (10) according to any of the preceding claims, characterized by , that the second evaporator (42) is designed as a chiller (42) through which the refrigerant and a coolant can flow. [5] Refrigerant circuit (10) according to any of the preceding claims, characterized by, that the refrigerant circuit (10) can be operated in a cooling mode in which the refrigerant compressed by the compressor (14) can be supplied exclusively to the refrigerant cooler (22), wherein in the cooling mode the refrigerant that can be supplied to the first evaporator (38) and / or the second evaporator (42) can be expanded by means of the second valve (30), and wherein in the cooling mode a flow direction of the refrigerant through the refrigerant cooler (22) is the same as a flow direction of the refrigerant through the refrigerant cooler (22) as is the case in the heat pump operation. [6] Motor vehicle (12) with a refrigerant circuit (10) according to one of the preceding claims, wherein the motor vehicle (12) is designed as an electric vehicle or as a hybrid vehicle. [7] Method for operating a refrigerant circuit (10) for a motor vehicle (12), in which a compressor (14) of the refrigerant circuit (10) supplies at least a partial flow of compressed refrigerant to a heat exchanger (16) of the refrigerant circuit (10) in heat pump operation, wherein the heat exchanger (16) is designed to heat an air flow (18) that can be introduced into a passenger compartment (20) of the motor vehicle (12) in heat pump operation, wherein the refrigerant circuit (10) comprises a refrigerant cooler (22) separate from the heat exchanger (16), which can be supplied with ambient air (24), characterized bythat a partial flow of compressed refrigerant is supplied to the refrigerant cooler (22), wherein the refrigerant circuit (10) comprises a first valve (28) which is arranged downstream of a refrigerant outlet (26) of the heat exchanger (16), and by means of which a pressure of the refrigerant in the heat exchanger (16) is set, wherein the first valve (28) is designed as an expansion device which has a variable cross-section through which the refrigerant flows, wherein the refrigerant circuit (10) comprises a second valve (30) which is arranged downstream of a refrigerant outlet (32) of the refrigerant cooler (22), and by means of which a pressure of the refrigerant in the refrigerant cooler (22) is set, wherein the second valve (30) is designed as an expansion device which has a variable cross-section through which the refrigerant flows, and wherein the refrigerant circuit (10) has a distribution valve (34).to which partial flows of refrigerant from the first valve (28) and from the second valve (30) are supplied, wherein a first evaporator (38) of the refrigerant circuit (10) is supplied with expanded refrigerant via a first outlet (36) of the distribution valve (34) and / or a second evaporator (42) of the refrigerant circuit (10) is supplied with expanded refrigerant via a second outlet (40) of the distribution valve (34), wherein the refrigerant circuit (10) has a further distribution valve (58) at a branch point of the refrigerant circuit (10), from which a first partial flow of the compressed refrigerant is supplied to the heat exchanger (16) and a second partial flow of the compressed refrigerant is supplied to the refrigerant cooler (22), by means of which the respective partial flows are adjusted,wherein the further distribution valve (58) simultaneously supplies respective partial flows of the compressed refrigerant to the heat exchanger (16) and the refrigerant cooler (22), wherein a control device (66) of the refrigerant circuit (10) adjusts the size of the partial flow to be supplied to the refrigerant cooler (22) by actuating the further distribution valve (58) depending on an excess of heat accumulating at the heat exchanger (16), and wherein the control device (66) actuates the first valve (28), the second valve (30), the distribution valve (34) and the compressor (14) according to the respective requirements.

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